Ectrodactyly

Last updated
Ectrodactyly
Main droite 1 an.jpg
Ectrodactyly and syndactyly on the hand of a one-year-old child
Specialty Medical genetics   OOjs UI icon edit-ltr-progressive.svg

Ectrodactyly, split hand, or cleft hand [1] (derived from Greek ektroma "miscarriage" and daktylos "finger") [2] involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). [3] The hands and feet of people with ectrodactyly (ectrodactyls) are often described as "claw-like" and may include only the thumb and one finger (usually either the little finger, ring finger, or a syndactyly of the two) with similar abnormalities of the feet. [4]

Contents

It is a substantial rare form of a congenital disorder in which the development of the hand is disturbed. It is a type I failure of formation – longitudinal arrest. [5] The central ray of the hand is affected and usually appears without proximal deficiencies of nerves, vessels, tendons, muscles and bones in contrast to the radial and ulnar deficiencies. The cleft hand appears as a V-shaped cleft situated in the centre of the hand. [6] The digits at the borders of the cleft might be syndactilyzed, and one or more digits can be absent. In most types, the thumb, ring finger and little finger are the less affected parts of the hand. [7] The incidence of cleft hand varies from 1 in 90,000 to 1 in 10,000 births depending on the used classification. Cleft hand can appear unilateral or bilateral, [6] and can appear isolated or associated with a syndrome.

Split hand/foot malformation (SHFM) is characterized by underdeveloped or absent central digital rays, clefts of hands and feet, and variable syndactyly of the remaining digits. SHFM is a heterogeneous condition caused by abnormalities at one of multiple loci, including SHFM1 (SHFM1 at 7q21-q22), SHFM2 (Xq26), SHFM3 (FBXW4/DACTYLIN at 10q24), SHFM4 (TP63 at 3q27), and SHFM5 (DLX1 and DLX 2 at 2q31). SHFM3 is unique in that it is caused by submicroscopic tandem chromosome duplications of FBXW4/DACTYLIN. SHFM3 is considered 'isolated' ectrodactyly and does not show a mutation of the tp63 gene.

Presentation

Ectrodactyly can be caused by various changes to 7q. When 7q is altered by a deletion or a translocation, ectrodactyly can sometimes be associated with hearing loss. [8] Ectrodactyly, or Split hand/split foot malformation (SHFM) type 1 is the only form of split hand/ malformation associated with sensorineural hearing loss. [8]

Genetics

Syndrome
Ectrodactyly–ectodermal dysplasia–cleft syndrome
Split-Hand-Foot Malformation Syndrome
Silver–Russell syndrome
Cornelia de Lange syndrome
Acrorenal syndrome
Focal dermal hypoplasia
Ectrodactyly and cleft palate syndrome
Ectrodactyly/mandibulofacial dysostosis
Ectrodactyly and macular dystrophy
Buttien-Fryns syndrome

A large number of human gene defects can cause ectrodactyly. The most common mode of inheritance is autosomal dominant with reduced penetrance, while autosomal recessive and X-linked forms occur more rarely. [9] Ectrodactyly can also be caused by a duplication on 10q24. Detailed studies of a number of mouse models for ectrodactyly have also revealed that a failure to maintain median apical ectodermal ridge (AER) signalling can be the main pathogenic mechanism in triggering this abnormality. [9]

A number of factors make the identification of the genetic defects underlying human ectrodactyly a complicated process: the limited number of families linked to each split hand/foot malformation (SHFM) locus, the large number of morphogens involved in limb development, the complex interactions between these morphogens, the involvement of modifier genes, and the presumed involvement of multiple gene or long-range regulatory elements in some cases of ectrodactyly. [9] In the clinical setting these genetic characteristics can become problematic and making predictions of carrier status and severity of the disease impossible to predict. [10]

In 2011, a novel mutation in DLX5 was found to be involved in SHFM. [11]

Ectrodactyly is frequently seen with other congenital anomalies. [9] Syndromes in which ectrodactyly is associated with other abnormalities can occur when two or more genes are affected by a chromosomal rearrangement. [9] Disorders associated with ectrodactyly include Ectrodactyly-Ectodermal Dysplasia-Clefting (EEC) syndrome, which is closely correlated to the ADULT syndrome and Limb-mammary (LMS) syndrome, Ectrodactyly-Cleft Palate (ECP) syndrome, Ectrodactyly-Ectodermal Dysplasia-Macular Dystrophy syndrome, Ectrodactyly-Fibular Aplasia/Hypoplasia (EFA) syndrome, and Ectrodactyly-Polydactyly. More than 50 syndromes and associations involving ectrodactyly are distinguished in the London Dysmorphology Database. [12]

Pathophysiology

The pathophysiology of cleft hand is thought to be a result of a wedge-shaped defect of the apical ectoderm of the limb bud (AER: apical ectodermal ridge). [6] Polydactyly, syndactyly and cleft hand can occur within the same hand, therefore some investigators suggest that these entities occur from the same mechanism. [6] This mechanism is not yet defined.

Genetics

The cause of cleft hand lies, for what is known, partly in genetics. The inheritance of cleft hand is autosomal dominant and has a variable penetrance of 70%. [6] Cleft hand can be a spontaneous mutation during pregnancy (de novo mutation). The exact chromosomal defect in isolated cleft hand is not yet defined. However, the genetic causes of cleft hand related to syndromes have more clarity. [13] The identified mutation for SHSF syndrome (split-hand/split-foot syndrome) a duplication on 10q24, and not a mutation of the tp63 gene as in families affected by EEC syndrome (ectrodactyly–ectodermal dysplasia–cleft syndrome). [13] The p63 gene plays a critical role in the development of the apical ectodermal ridge (AER), this was found in mutant mice with dactylaplasia. [6]

Embryology

Some studies [13] [14] [15] have postulated that polydactyly, syndactyly and cleft hand have the same teratogenic mechanism. In vivo tests showed that limb anomalies were found alone or in combination with cleft hand when they were given Myleran. These anomalies take place in humans around day 41 of gestation. [13]

Diagnosis

Classification

There are several classifications for cleft hand, but the most used classification is described by Manske and Halikis [16] see table 3. This classification is based on the first web space. The first web space is the space between the thumb and the index finger.

Table 3: Classification for cleft hand described by Manske and Halikis

TypeDescription [17] [18] Characteristics [18]
INormal webThumb web space not narrowed
IIAMildly narrowed webThumb web space mildly narrowed
IIBSeverely narrowed webThumb web space severely narrowed
IIISyndactylized webThumb and index rays syndactylized, web space obliterated
IVMerged webIndex ray suppressed, thumb web space is merged with the cleft
VAbsent webThumb elements suppressed, ulnar rays remain, thumb web space no longer present

Treatment

The treatment of cleft hand is usually invasive and can differ each time because of the heterogeneity of the condition. The function of a cleft hand is mostly not restricted, yet improving the function is one of the goals when the thumb or first webspace is absent.[ citation needed ]

The social and stigmatising aspects of a cleft hand require more attention. The hand is a part of the body which is usually shown during communication. When this hand is obviously different and deformed, stigmatisation or rejection can occur. Sometimes, in families with cleft hand with good function, operations for cosmetic aspects are considered marginal [6] and the families choose not to have surgery.[ citation needed ]

Indications

Surgical treatment of the cleft hand is based on several indications: [6]

Aesthetical aspects

Timing of surgical interventions

The timing of surgical interventions is debatable. Parents have to decide about their child in a very vulnerable time of their parenthood. Indications for early treatment are progressive deformities, such as syndactyly between index and thumb or transverse bones between the digital rays. [6] Other surgical interventions are less urgent and can wait for 1 or 2 years.[ citation needed ]

Classification and treatment

When surgery is indicated, the choice of treatment is based on the classification. Table 4 shows the treatment of cleft hand divided into the classification of Manske and Halikis. Techniques described by Ueba, Miura and Komada and the procedure of Snow-Littler are guidelines; since clinical and anatomical presentation within the types differ, the actual treatment is based on the individual abnormality.[ citation needed ]

Table 4: Treatment based on the classification of Manske and Halikis

TypeTreatment
I/IIAReconstruction of the transverse metacarpal ligament [19]
IIB/IIITransposition of the index metacarpal with reconstruction of the thumb webspace [19]
IVMobility and/or position of the thumb of ulnar digit to promote pinch and grasp [16]
VThere is no cleft or web space and the thumb is very deficient. This hand requires consideration of creating a radial digit [16]

Snow-Littler

The goal of this procedure is to create a wide first web space and to minimise the cleft in the hand. The index digit will be transferred to the ulnar side of the cleft. Simultaneously a correction of index malrotation and deviation is performed. [6] To minimise the cleft, it is necessary to fix together the metacarpals which used to border the cleft. Through repositioning flaps, the wound can be closed.[ citation needed ]

Ueba

Ueba described a less complicated surgery. [6] Transverse flaps are used to resurface the palm, the dorsal side of the transposed digit and the ulnar part of the first web space. A tendon graft is used to connect the common extensor tendons of the border digits of the cleft to prevent digital separation during extension. The closure is simpler, but has cosmetic disadvantage because of the switch between palmar and dorsal skin.[ citation needed ]

Miura and Komada

The release of the first webspace has the same principle as the Snow-Littler procedure. The difference is the closure of the first webspace; this is done by simple closure or closure with Z-plasties. [6]

History

Ectrodactyly in all extremities; only eight total digits present, 1870 Malformation of fingers and toes.jpg
Ectrodactyly in all extremities; only eight total digits present, 1870
Monodactyly of both hands; only two fingers present, 1897 Gould Pyle 124.jpg
Monodactyly of both hands; only two fingers present, 1897

Literature shows that cleft hand is described centuries ago. In City of God (426 A.D.), St. Augustine remarks:

At Hippo-Diarrhytus there is a man whose hands are crescent-shaped, and have only two fingers each, and his feet similarly formed. [20]

The first modern reference to what might be considered a cleft hand was by Ambroise Paré in 1575. Hartsink (1770) wrote the first report of true cleft hand. In 1896, the first operation of the cleft hand was performed by Doctor Charles N. Dowed of New York City. [16] However, the first certain description of what we know as a cleft hand as we know it today was described at the end of the 19th century. [16]

Symbrachydactyly

Typical cleft handAtypical cleft hand (symbrachydactyly)
Typical hand was manifest in the complete or incomplete absence of the middle finger [21] Atypical hand had a more severe manifestation in which there was varying absence of the central index, middle and ring finger rays [21]
V-shaped cleft [6] U-shaped cleft [6]
One to four limbs involved [6] One limb involved (no feet) [6]
Higher incidence [16] Lower incidence [16]
Autosomal dominant [6] Sporadic [6]
Suppression progresses in a radial direction so that in the monodactylous form the most ulnar finger is preserved [6] Suppression progresses in a more ulnar direction; therefore in the monodactylous form the thumb is usually the last remaining digit [6]

Historically, a U-type cleft hand was also known as atypical cleft hand. The classification in which typical and atypical cleft hand are described was mostly used for clinical aspects and is shown in table 1. Nowadays, this "atypical cleft hand" is referred to as symbrachydactyly and is not a subtype of cleft hand.[ citation needed ]

Notable cases

Vadoma people with ectrodactyly Vadoma 1..jpg
Vadoma people with ectrodactyly

Animals

Ectrodactyly is not only a genetic characteristic in humans, but can also occur in frogs and toads, [24] mice, [25] salamanders, [26] cows, [9] chickens, [9] rabbits, [9] marmosets, [9] cats and dogs, [27] and even West Indian manatees. [9] The following examples are studies showing the natural occurrence of ectrodactyly in animals, without the disease being reproduced and tested in a laboratory.[ citation needed ] In all three examples we see how rare the actual occurrence of ectrodactyly is.

Wood frog

The Department of Biological Sciences at the University of Alberta in Edmonton, Alberta performed a study to estimate deformity levels in wood frogs in areas of relatively low disturbance. [24] After roughly 22,733 individuals were examined during field studies, it was found that only 49 wood frogs had the ectrodactyly deformity. [24]

Salamanders

In a study performed by the Department of Forestry and Natural Resources at Purdue University, approximately 2000 salamanders (687 adults and 1259 larvae) were captured from a large wetland complex and evaluated for malformations. [26] Among the 687 adults, 54 (7.9%) were malformed. Of these 54 adults, 46 (85%) had missing (ectrodactyly), extra (polyphalangy) or dwarfed digits (brachydactyly). [26] Among the 1259 larvae, 102 were malformed, with 94 (92%) of the malformations involving ectrodactyly, polyphalangy, and brachydactyly. [26] Results showed few differences in the frequency of malformations among life-history changes, suggesting that malformed larvae do not have substantially higher mortality than their adult conspecifics. [26]

Cats and dogs

Davis and Barry 1977 tested allele frequencies in domestic cats. Among the 265 cats observed, there were 101 males and 164 females. Only one cat was recorded to have the ectrodactyly abnormality, [28] illustrating this rare disease.

According to M.P. Ferreira, a case of ectrodactyly was found in a two-month-old male mixed Terrier dog. [29] In another study, Carrig and co-workers also reported a series of 14 dogs [30] with this abnormality proving that although ectrodactyly is an uncommon occurrence for dogs, it is not entirely unheard of.

See also

Related Research Articles

<span class="mw-page-title-main">Polydactyly</span> Physical anomaly involving extra fingers or toes

Polydactyly or polydactylism, also known as hyperdactyly, is an anomaly in humans and animals resulting in supernumerary fingers and/or toes. Polydactyly is the opposite of oligodactyly.

<span class="mw-page-title-main">Apert syndrome</span> Congenital disorder of the skull and digits

Apert syndrome is a form of acrocephalosyndactyly, a congenital disorder characterized by malformations of the skull, face, hands and feet. It is classified as a branchial arch syndrome, affecting the first branchial arch, the precursor of the maxilla and mandible. Disturbances in the development of the branchial arches in fetal development create lasting and widespread effects.

<span class="mw-page-title-main">Carpenter syndrome</span> Medical condition

Carpenter syndrome, also called acrocephalopolysyndactyly type II, is an extremely rare autosomal recessive congenital disorder characterized by craniofacial malformations, obesity, syndactyly, and polydactyly. Acrocephalopolysyndactyly is a variation of acrocephalosyndactyly that presents with polydactyly.

<span class="mw-page-title-main">Popliteal pterygium syndrome</span> Medical condition

Popliteal pterygium syndrome (PPS) is an inherited condition affecting the face, limbs, and genitalia. The syndrome goes by a number of names including the popliteal web syndrome and, more inclusively, the facio-genito-popliteal syndrome. The term PPS was coined by Gorlin et al. in 1968 on the basis of the most unusual anomaly, the popliteal pterygium.

<span class="mw-page-title-main">Greig cephalopolysyndactyly syndrome</span> Medical condition

Greig cephalopolysyndactyly syndrome is a disorder that affects development of the limbs, head, and face. The features of this syndrome are highly variable, ranging from very mild to severe. People with this condition typically have one or more extra fingers or toes (polydactyly) or an abnormally wide thumb or big toe (hallux).

<span class="mw-page-title-main">Duane-radial ray syndrome</span> Medical condition

Duane-radial ray syndrome, also known as Okihiro syndrome, is a rare autosomal dominant disorder that primarily affects the eyes and causes abnormalities of bones in the arms and hands. This disorder is considered to be a SALL4-related disorder due to the SALL4 gene mutations leading to these abnormalities. It is diagnosed by clinical findings on a physical exam as well as genetic testing and imaging. After being diagnosed, there are other evaluations that one may go through in order to determine the extent of the disease. There are various treatments for the symptoms of this disorder.

<span class="mw-page-title-main">Ectrodactyly–ectodermal dysplasia–cleft syndrome</span> Medical condition

Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome and split hand–split foot–ectodermal dysplasia–cleft syndrome is a rare form of ectodermal dysplasia, an autosomal dominant disorder inherited as a genetic trait. EEC is characterized by the triad of ectrodactyly, ectodermal dysplasia, and facial clefts. Other features noted in association with EEC include vesicoureteral reflux, recurrent urinary tract infections, obstruction of the nasolacrimal duct, decreased pigmentation of the hair and skin, missing or abnormal teeth, enamel hypoplasia, absent punctae in the lower eyelids, photophobia, occasional cognitive impairment and kidney anomalies, and conductive hearing loss.

Amastia refers to a rare clinical anomaly in which both internal breast tissue and the visible nipple are absent on one or both sides. It affects both men and women. Amastia can be either isolated or comorbid with other syndromes, such as ectodermal dysplasia, Syndactyly and lipoatrophic diabetes. This abnormality can be classified into various types, and each could result from different pathologies. Amastia differs from amazia and athelia. Amazia is the absence of one or both mammary glands but the nipples remain present, and athelia is the absence of one or both nipples, but the mammary gland remains.

<span class="mw-page-title-main">Dysmelia</span> Congenital disorder of a limb

Dysmelia is a congenital disorder of a limb resulting from a disturbance in embryonic development.

Congenital limb deformities are congenital musculoskeletal disorders which primarily affect the upper and lower limbs.

<span class="mw-page-title-main">Frontonasal dysplasia</span> Medical condition

Frontonasal dysplasia (FND) is a congenital malformation of the midface. For the diagnosis of FND, a patient should present at least two of the following characteristics: hypertelorism, a wide nasal root, vertical midline cleft of the nose and/or upper lip, cleft of the wings of the nose, malformed nasal tip, encephalocele or V-shaped hair pattern on the forehead. The cause of FND remains unknown. FND seems to be sporadic (random) and multiple environmental factors are suggested as possible causes for the syndrome. However, in some families multiple cases of FND were reported, which suggests a genetic cause of FND.

<span class="mw-page-title-main">EEM syndrome</span> Medical condition

EEM syndrome is an autosomal recessive congenital malformation disorder affecting tissues associated with the ectoderm, and also the hands, feet and eyes.

<span class="mw-page-title-main">Oligodactyly</span> Medical condition

Oligodactyly is the presence of fewer than five fingers or toes on a hand or foot.

<span class="mw-page-title-main">Triphalangeal thumb</span> Congenital malformation

Triphalangeal thumb (TPT) is a congenital malformation where the thumb has three phalanges instead of two. The extra phalangeal bone can vary in size from that of a small pebble to a size comparable to the phalanges in non-thumb digits. The true incidence of the condition is unknown, but is estimated at 1:25,000 live births. In about two-thirds of the patients with triphalangeal thumbs, there is a hereditary component. Besides the three phalanges, there can also be other malformations. It was first described by Columbi in 1559.

<span class="mw-page-title-main">Constriction ring syndrome</span> Medical condition

Constriction ring syndrome (CRS) is a congenital disorder with unknown cause. Because of the unknown cause there are many different, and sometimes incorrect names. It is a malformation due to intrauterine bands or rings that give deep grooves in, most commonly, distal extremities like fingers and toes. In rare cases the constriction ring can form around other parts of the fetus and cause amputation or even intrauterine death. The anatomy proximal to the site of constriction is developmentally normal. CRS can be associated with other malformations with club foot being most common. The precise configuration of the bands, lymphedema, and character of the amputations are not predictable and vary with each individual patient. Also, more than one extremity is usually affected, and it is rare for only one ring to present as an isolated malformation with no other manifestation of this syndrome.

<span class="mw-page-title-main">Acro–dermato–ungual–lacrimal–tooth syndrome</span> Rare human genetic disease

Acro–dermato–ungual–lacrimal–tooth syndrome is a rare genetic disease. It is an autosomal dominant form of ectodermal dysplasia, a group of disorders that affects the hair, teeth, nails, sweat glands, and extremities. The syndrome arises from a mutation in the TP63 gene. This disease was previously thought to be a form of ectrodactyly–ectodermal dysplasia–cleft syndrome (EEC), but was classified as a different disease in 1993 by Propping and Zerres.

<span class="mw-page-title-main">Polysyndactyly</span> Medical condition

Polysyndactyly is a congenital anomaly, combining polydactyly and syndactyly, in which affected individuals have an extra finger or toe that is connected, via fusing or webbing, to an adjacent digit.

References

  1. ↑ Giele, Henk; Cassell, Oliver (2008). Plastic and Reconstructive Surgery. Oxford: Oxford University Press. p. 197. ISBN   978-0-19-263222-7.
  2. ↑ Durowaye, Mathew; Adegboye, Abdulrasheed; Mokuolu, Olugbenga Ayodeji; Adeboye, Muhammed; Yahaya-Kongoila, Sefiyah; Adaje, Adeline; Adesiyun, Omotayo; Ernest, Samuel Kolade (2011). "Familial Ectrodactyly Syndrome in a Nigerian Child: A Case Report". Oman Medical Journal. 26 (4): 275–8. doi:10.5001/omj.2011.67. PMC   3191709 . PMID   22043435.
  3. ↑ Moerman, P.; Fryns, J.P. (1998). "Ectodermal dysplasia, Rapp–Hodgkin type in a mother and severe ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC) in her child". American Journal of Medical Genetics Part A . 63 (3): 479–81. doi:10.1002/(SICI)1096-8628(19960614)63:3<479::AID-AJMG12>3.0.CO;2-J. PMID   8737656.
  4. ↑ Peterson-Falzone, Sally J.; Hardin-Jones, Mary A.; Karnell, Michael P.; McWilliams, Betty Jane (2001). Cleft Palate Speech . Mosby. ISBN   978-0-8151-3153-3.
  5. ↑ Congenital Hand Deformities at eMedicine
  6. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Kay, Simon P.; McCombe, David (2005). "Central hand deficiencies". In Green, David P.; Hotchkiss, Robert N.; Pederson, William C.; et al. (eds.). Green's Operative Hand Surgery (5th ed.). Philadelphia: Elsevier/ Churchill Livingstone. pp. 1404–15. ISBN   978-0-443-06626-9.
  7. ↑ Upton, Joseph; Taghinia, Amir H. (2010). "Correction of the Typical Cleft Hand". The Journal of Hand Surgery. 35 (3): 480–5. doi:10.1016/j.jhsa.2009.12.021. PMID   20138711.
  8. 1 2 Wieland, I.; Muschke, P; Jakubiczka, S; Volleth, M; Freigang, B; Wieacker, PF; et al. (2004). "Refinement of the deletion in 7q21.3 associated with split hand/foot malformation type 1 and Mondini dysplasia". Journal of Medical Genetics . 41 (5): e54. doi:10.1136/jmg.2003.010587. PMC   1735762 . PMID   15121782.
  9. 1 2 3 4 5 6 7 8 9 10 Pascal, H.G.; et al. (2003). "Pathogenesis of split-hand/split-foot malformation". Human Molecular Genetics . 12 (1): R51–R60. doi: 10.1093/hmg/ddg090 . PMID   12668597.
  10. ↑ Scherer, Stephen; Cheung, J; MacDonald, JR; Osborne, LR; Nakabayashi, K; Herbrick, JA; Carson, AR; Parker-Katiraee, L; et al. (2003). "Human Chromosome 7: DNA Sequence and Biology". Science . 300 (5620): 767–772. Bibcode:2003Sci...300..767S. doi:10.1126/science.1083423. PMC   2882961 . PMID   12690205.
  11. ↑ Shamseldin, Hanan E; Faden Maha A; Alashram Walid; Alkuraya Fowzan S (Nov 2011). "Identification of a novel DLX5 mutation in a family with autosomal recessive split hand and foot malformation". Journal of Medical Genetics. 49 (1): 16–20. doi:10.1136/jmedgenet-2011-100556. PMID   22121204. S2CID   25692622.
  12. ↑ Winter, R.M.; Baraitser, M. (August 1987). "The London Dysmorphology Database". Journal of Medical Genetics . 24 (8): 509–510. doi:10.1136/jmg.24.8.509. PMC   1050214 . PMID   3656376.
  13. 1 2 3 4 Katarincic, Julia A. (2003). Cleft Hand. American Society for Surgery of the Hand.[ page needed ]
  14. ↑ Naruse, Takuji; Takahara, Masatoshi; Takagi, Michiaki; Ogino, Toshihiko (2007). "Early Morphological Changes Leading to Central Polydactyly, Syndactyly, and Central Deficiencies: An Experimental Study in Rats". The Journal of Hand Surgery. 32 (9): 1413–7. doi:10.1016/j.jhsa.2007.06.017. PMID   17996777.
  15. ↑ Naruse, Takuji; Takahara, Masatoshi; Takagi, Michiaki; Oberg, Kerby C.; Ogino, Toshihiko (2007). "Busulfan-induced central polydactyly, syndactyly and cleft hand or foot: A common mechanism of disruption leads to divergent phenotypes". Development, Growth & Differentiation. 49 (6): 533–41. doi: 10.1111/j.1440-169X.2007.00949.x . PMID   17661743.
  16. 1 2 3 4 5 6 7 Barsky, Arthur J (1964). "Cleft hand: Classification, incidence and treatment: review of the literature and report of nineteen cases". The Journal of Bone and Joint Surgery. 46: 1707–20. doi:10.2106/00004623-196446080-00006. PMID   14239859.[ permanent dead link ]
  17. ↑ Falliner AA., Analysis of anatomic variations in cleft hands, J Hand Surg Am. 2004 Nov;29(6):994-1001
  18. 1 2 Manske, Paul R.; Halikis, Mark N. (1995). "Surgical classification of central deficiency according to the thumb web". The Journal of Hand Surgery. 20 (4): 687–97. doi:10.1016/S0363-5023(05)80293-X. PMID   7594304.
  19. 1 2 Manske, Paul R.; Goldfarb, Charles A. (2009). "Congenital Failure of Formation of the Upper Limb". Hand Clinics. 25 (2): 157–70. doi:10.1016/j.hcl.2008.10.005. PMID   19380058.
  20. ↑ City of God, Book XVI, Chapter 8
  21. 1 2 Jones, Neil F; Kono, Michiyuki (2004). "Cleft hands with six metacarpals". The Journal of Hand Surgery. 29 (4): 720–6. doi:10.1016/j.jhsa.2004.04.002. PMID   15249100.
  22. ↑ "Medical Mystery: Ectrodactyly". ABC News. January 27, 2007.
  23. ↑ Farrell HB (1984). "The two-toed Wadoma--familial ectrodactyly in Zimbabwe". S. Afr. Med. J. 65 (13): 531–3. PMID   6710256.
  24. 1 2 3 Eaton, Brian R.; Eaves, Sara; Stevens, Cameron; Puchniak, Allison; Paszkowski, Cynthia A.; et al. (2004). "Deformity Levels in Wild Populations of the Wood Frog (Rana sylvatica) in Three Ecoregions of Western Canada". Journal of Herpetology . 38 (2): 283–287. doi:10.1670/95-03N. S2CID   86275852.
  25. ↑ Manson, Jeanne; Dourson, Michael L.; Smith, Carl C. (1977). "Effects of Cytosine Arabinoside on In vivo and In vitro Mouse limb Development". In Vitro. 13 (7): 434–442. doi:10.1007/BF02615104. PMID   885563. S2CID   10311465.
  26. 1 2 3 4 5 Williams, Rod N; Bos, David H; Gopurenko, David; DeWoody, J Andrew (2008). "Amphibian malformations and inbreeding". Biology Letters. 4 (5): 549–52. doi:10.1098/rsbl.2008.0233. PMC   2610075 . PMID   18593670.
  27. ↑ Jezyk, P.F. (1985). Constitutional Disorders of the Skeleton in Dogs and Cats: Textbook of Small Animal Orthopedics. Ithaca, New York: International Veterinary Information Service.
  28. ↑ Davis, Brian; Davis, Barry (1977). "Allele frequencies in a cat population in Budapest". Journal of Heredity . 68 (1): 31–34. doi:10.1093/oxfordjournals.jhered.a108768. PMID   864231.
  29. ↑ Ferreira, M.P.; Alievi, M.M.; Beck, C.A.C.; Voll, J.; Muccillo, M.S.; Gomes, C. (2007). "Ectrodactilia em cão: relato de caso". Arquivo Brasileiro de Medicina Veterinária e Zootecnia. 59 (4): 910–3. doi: 10.1590/S0102-09352007000400015 . hdl: 10183/76981 .
  30. ↑ Carrig, ColinB.; Wortman, JeffreyA.; Morris, EarlL.; Blevins, WilliamE.; Root, CharlesR.; Hanlon, GriseldaF.; Suter, PeterF. (1981). "Ectrodactyly (Split-hand deformity) in the dog". Veterinary Radiology. 22 (3): 123–44. doi:10.1111/j.1740-8261.1981.tb01363.x.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.