Brachydactyly type D | |
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Other names | Clubbed thumb, [1] thumb head, [2] short thumb, [3] [1] potter's thumb, [1] royal thumb, murderer's thumb, [1] hammer thumb, stubbed thumb, [4] stub thumb [5] [6] |
Unilateral brachydactyly type D in a 15-year-old female | |
X-ray of a regular thumb (left) and a thumb with brachydactyly type D (right) showing distal phalange brachyphalangy of said thumb. | |
Specialty | Medical genetics |
Brachydactyly type D, also known as short thumb, [3] [1] stub thumb, [5] [6] or clubbed thumb, [5] [6] is a genetic trait recognised by a thumb being relatively short and round with an accompanying wider nail bed. The distal phalanx of such thumbs is approximately two-thirds the length of full-length thumbs. It is the most common type of shortness of digits (brachydactyly), affecting approximately 2% of the population. It is associated with the HOXD13 gene, located on chromosome 2q31.1. [7]
Brachydactyly type D is a skeletal condition which exhibits a 'partial fusion or premature closing of the epiphysis with the distal phalanx of the thumb', according to Goodman et alia (1965). [6] J.K. Breithenbecher (1923) found that distal phalanges of short thumbs were one-half the length of full-length thumbs, while R.M. Stecher (1957) claimed that it is approximately two-thirds. The condition may either be unilateral (affecting one thumb) or bilateral (affecting both). [6]
A genetic trait, brachydactyly type D exhibits autosomal dominance and is commonly developed or inherited independently of other hereditary traits. The condition is associated with the HOXD13 gene, which is central in digital formation and growth. [5]
Various other studies supported an autosomal dominant pattern with reduced penetrance. [8]
About 3% of Israeli Arabs had one or two short thumbs, compared with 1.6% among Ashkenazi as well as non-Ashkenazi Jews. [6] However, as the survey's Arab test persons were mainly recruited from a handful of large and closely related clans living in a particular village, said percentage should be "considered with some reservation".
Cases of short thumbs have also been found in Eastern Nepal for Jirel ethnic individuals from their participation in various epidemiologic studies. Some studies included taking radiographs of hands and wrists to examine their skeletal structure. Of the studied sample (which included 2,130 participants; 1,161 female and 969 male), 3.55% were found to have brachydactyly type D. [9]
The condition is known by numerous names including clubbed thumb or club thumb. [10] [11] American researcher R.A. Hefner used the terms "short thumb" and "brachymegalodactylism" in 1924, [3] and "short thumb" has continued to be used in a few other studies since then, including the study that defined Rubinstein–Taybi syndrome in 1963. [1] "Stub thumb" is the common term preferred by the online database Online Mendelian Inheritance in Man [5] and was first used in a 1965 study. [6] Stub thumbs have also been called murderer's thumb (allegedly among fortune tellers), [6] hammer thumb, bohemian thumb, and potter's thumb. [5]
Brachydactyly is a medical term denoting the presence of abnormally short digits at birth. The shortness is relative to the length of other long bones and other parts of the body. Brachydactyly is an inherited, dominant trait. It most often occurs as an isolated dysmelia, but can also occur with other anomalies as part of many congenital syndromes. Brachydactyly may also be a signal that one is at risk for congenital heart disease due to the association between congenital heart disease and Carpenter syndrome and the link between Carpenter syndrome and brachydactyly.
Cri du chat syndrome is a rare genetic disorder due to a partial chromosome deletion on chromosome 5. Its name is a French term referring to the characteristic cat-like cry of affected children. It was first described by Jérôme Lejeune in 1963. The condition affects an estimated 1 in 50,000 live births across all ethnicities and is more common in females by a 4:3 ratio.
Julia Bell MA Dubl (1901) MRCS LRCP (1920) MRCP (1926) FRCP (1938) was one of the pioneers of eugenics and human genetics. Her early career as a statistical assistant to Karl Pearson (1857–1936) marked the beginning of a lifelong professional association with the Galton Laboratory for National Eugenics at University College London. Bell's work as a human geneticist was based on her statistical investigations into the inheritance of anomalies and diseases of the eye, nervous diseases, muscular dystrophies, and digital anomalies.
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).
Oculocerebrorenal syndrome is a rare X-linked recessive disorder characterized by congenital cataracts, hypotonia, intellectual disability, proximal tubular acidosis, aminoaciduria and low-molecular-weight proteinuria. Lowe syndrome can be considered a cause of Fanconi syndrome.
22q13 deletion syndrome, known as Phelan–McDermid syndrome (PMS), is a genetic disorder caused by deletions or rearrangements on the q terminal end of chromosome 22. Any abnormal genetic variation in the q13 region that presents with significant manifestations (phenotype) typical of a terminal deletion may be diagnosed as 22q13 deletion syndrome. There is disagreement among researchers as to the exact definition of 22q13 deletion syndrome. The Developmental Synaptopathies Consortium defines PMS as being caused by SHANK3 mutations, a definition that appears to exclude terminal deletions. The requirement to include SHANK3 in the definition is supported by many but not by those who first described 22q13 deletion syndrome.
Buschke–Ollendorff syndrome (BOS) is a rare genetic skin disorder associated with LEMD3 that typically presents with widespread painless papules.
Homeobox protein Hox-D13 is a protein that in humans is encoded by the HOXD13 gene. This gene belongs to the homeobox family of genes. The homeobox genes encode a highly conserved family of transcription factors that play an important role in morphogenesis in all multicellular organisms.
Cooks syndrome is a hereditary disorder which is characterized in the hands by bilateral nail hypoplasia on the thumb, index finger, and middle finger, absence of fingernails (anonychia) on the ring finger and little finger, lengthening of the thumbs, and bulbousness of the fingers. In the feet, it is characterized by absence of toenails and absence/hypoplasia of the distal phalanges. In the second study of this disorder, it was found that the intermediate phalanges, proximal phalanges, and metacarpals were unaffected.
Hereditary neuropathy with liability to pressure palsy (HNPP) is a peripheral neuropathy, a condition that affects the nerves. Pressure on the nerves can cause tingling sensations, numbness, pain, weakness, muscle atrophy and even paralysis of the affected area. In normal individuals, these symptoms disappear quickly, but in sufferers of HNPP even a short period of pressure can cause the symptoms to occur. Palsies can last from minutes or days to weeks or even months.
MURCS association is a very rare developmental disorder that primarily affects the reproductive and urinary systems involving MUllerian agenesis, Renal agenesis, Cervicothoracic Somite abnormalities. It affects only females.
Jordans' anomaly is a familial abnormality of white blood cell morphology. Individuals with this condition exhibit persistent vacuolation of granulocytes and monocytes in the peripheral blood and bone marrow. Jordans' anomaly is associated with neutral lipid storage diseases.
Familial opposable triphalangeal thumb duplication is a limb malformation syndrome and a type of pre-axial polydactyly, characterized by having duplicated opposable triphalangeal thumbs. This condition can be a symptom of other genetic disorders, such as Holt–Oram syndrome and Fanconi anemia. This trait is autosomal dominant and often runs in families. Sometimes big toe duplication, post-axial polydactyly, and syndactyly of the hand and feet can occur alongside this malformation Approximately 20 families with the condition have been described in medical literature.
Hirschsprung's disease-type D brachydactyly syndrome is a very rare genetic disorder which is characterized by the partial absence of nerves in the intestines and hypoplasia of the thumb's distal phalange. It has been described in 4 males from a 2-generation American family. The inheritance pattern was hypothesized to be either X-linked recessive or autosomal dominant with reduced penetrance.
Brachydactyly-long thumb syndrome is a very rare genetic disorder which is characterized by symmetric brachydactyly of the fingers accompanied by an abnormally long thumb, hypomobility of the shoulder and metacarpo-phalangeal joints, and heart conduction defects. Small feet and hands, small shoulders accompanied with short clavicles, clinodactyly, pectus excavatum, mild limb shortening, cardiomegaly, and pulmonic stenosis murmur have also been reported. It was first discovered when D W Hollister et al. described 4 affected members belonging to a 3-generation family. No new cases have been reported since 1981. This disorder is inherited in an autosomal dominant manner.
Du Pan syndrome, also known as fibular aplasia-complex brachydactyly syndrome, is an extremely rare genetic condition. Unlike other rare genetic conditions, Du Pan syndrome does not affect brain function or the appearance of the head and trunk. This condition is associated with alterations to the GDF5 gene. The way that this condition is passed on from generation to generation varies, but it is most commonly inherited in an autosomal recessive manner, meaning two copies of the same version of the gene are required to show this condition. Rare cases exist where the mode of inheritance is autosomal dominant, which means having only one version of the gene is enough to cause this condition.
Kirner's deformity, also known as dystelephangy, is an uncommon genetic hand malformation which is characterized by a radial and volar curvature of the distal phalange of the fifth (pinky) finger. It is merely cosmetic and doesn't affect hand function.
Triphalangeal thumbs-brachyectrodactyly syndrome is a very rare limb malformation syndrome of genetic origin which is characterized by polydactyly, syndactyly, brachydactyly, ectrodactyly, triphalangeal thumb and polyphalangism. Onychodystrophy and anonychia are also seen often. 27 cases from seven families from Mexico and the United States have been described in medical literature. It is inherited in an autosomal dominan manner and thought to be caused by mutations in the HOXD13 gene, in chromosome 2.
Heart-hand syndrome, Slovenian type is a rare autosomal dominant genetic disorder belonging to the heart-hand syndromes.