Cousin syndrome is a genetic condition characterized by short stature at birth, a short neck with low-positioned external ears, as well as congenital malformations of the skeletal system affecting the shoulders, the pelvis, the neck, and the limbs (MIM number 260660). [1] [2] The condition determines physical disability, particularly affecting deambulation, and hearing loss while intelligence is not affected.
The condition was originally described in 1982 by Jacques Cousin, physician in Lilles, France, and colleagues as "familial pelvi-scapular dysplasia with dwarfism and dysmorphisms". [3] Some sporadic patients reported in the medical literature as "pelvic-shoulder dysplasia" or similar diagnoses may in fact have had Cousin syndrome. In 2008, the group of Andrea Superti-Furga showed that the condition was caused by biallelic inactivating variants in the gene coding for the T-box transcription factor, TBX15. [4] They also proposed to name the condition "Cousin syndrome" because the name "pelviscapular dysplasia" is too restrictive. The incidence of the condition is not known but it seems to be very rare, with only a single further molecularly confirmed individual reported in 2015. [5] An important differential diagnosis in the newborn and infant is campomelic dysplasia, where hypoplasia of the scapulae and of the iliac bones with femoral dislocation may also occur. Campomelic dysplasia, caused by monoallelic variants in and around the SOX9 gene, is less rare than Cousin syndrome. [6]
Spondyloperipheral dysplasia is an autosomal dominant disorder of bone growth. The condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly). Some affected individuals also have other skeletal abnormalities, short stature, nearsightedness (myopia), hearing loss, and mental retardation. Spondyloperipheral dysplasia is a subtype of collagenopathy, types II and XI.
Autosomal recessive multiple epiphyseal dysplasia (ARMED), also called epiphyseal dysplasia, multiple, 4 (EDM4), multiple epiphyseal dysplasia with clubfoot or –with bilayered patellae, is an autosomal recessive congenital disorder affecting cartilage and bone development. The disorder has relatively mild signs and symptoms, including joint pain, scoliosis, and malformations of the hands, feet, and knees.
Campomelic dysplasia (CMD) is a genetic disorder characterized by bowing of the long bones and many other skeletal and extraskeletal features. It can be lethal in the neonatal period due to respiratory insufficiency, but the severity of the disease is variable, and a significant proportion of patients survive into adulthood. The name is derived from the Greek roots campo, meaning bent, and melia, meaning limb. An unusual aspect of the disease is that up to two-thirds of affected 46,XY genotypic males display a range of disorders of sexual development (DSD) and genital ambiguities or may even develop as normal phenotypic females as in complete 46 XY sex reversal. An atypical form of the disease with absence of bowed limbs is called, prosaically, acampomelic campomelic dysplasia (ACD) and is found in about 10% of patients, particularly those surviving the neonatal period.
RNA component of mitochondrial RNA processing endoribonuclease, also known as RMRP, is a human gene.
Parastremmatic dwarfism is a rare bone disease that features severe dwarfism, thoracic kyphosis, a distortion and twisting of the limbs, contractures of the large joints, malformations of the vertebrae and pelvis, and incontinence. The disease was first reported in 1970 by Leonard Langer and associates; they used the term parastremmatic from the Greek parastremma, or distorted limbs, to describe it. On X-rays, the disease is distinguished by a "flocky" or lace-like appearance to the bones. The disease is congenital, which means it is apparent at birth. It is caused by a mutation in the TRPV4 gene, located on chromosome 12 in humans. The disease is inherited in an autosomal dominant manner.
T-box transcription factor TBX15 is protein that is encoded in humans by the Tbx15 gene, mapped to Chromosome 3 in mice and Chromosome 1 in humans. Tbx15 is a transcription factor that plays a key role in embryonic development. Like other members of the T-box subfamily, Tbx15 is expressed in the notochord and primitive streak, where it assists with the formation and differentiation of the mesoderm. It is steadily downregulated after segmentation of the paraxial mesoderm.
Ischiopatellar dysplasia is a rare autosomal dominant disorder characterized by a hypoplasia of the patellae as well as other bone anomalies, especially concerning the pelvis and feet. It is also known as small patella syndrome, with earlier synonyms being Scott-Taor syndrome, Coxo-podo-patellar syndrome, Patella aplasia, coxa vara, tarsal synostosis, Congenital coxa vara, patella aplasia and tarsal synostosis ischiocoxopodopatellar syndrome.
Atelosteogenesis type I is a rare autosomal dominant condition. This condition is evident at birth and is associated with a very poor prognosis for the baby. It may be diagnosed antenatally.
Family with sequence similarity 111 member A is a protein that in humans is encoded by the FAM111A gene.
Andrea Superti-Furga is a Swiss-Italian pediatrician, geneticist and molecular biologist. He is the head of the Division of Genetic Medicine at the Lausanne University Hospital (CHUV) and a professor at the Faculty of Medicine and Biology of the University of Lausanne.
Cousin–Walbraum–Cegarra syndrome is a rare genetic and congenital disorder which consists of facial dysmorphia, congenital dwarfism, pelvic and scapular dysplasia, and growth plate abnormalities. In March 1982, medical literature described the case of a North African sister and brother from healthy consanguineous parents, both having the same symptoms, it was suggested that this disorder was inherited in an autosomal recessive fashion. Since then, only 10 cases have been reported in medical literature.
Otofaciocervical syndrome, also known as Fara Chlupackova syndrome, are a small group of rare developmental disorders of genetic origin which are characterized by facial dysmorphisms, long neck, preauricular and/or branchial pits, cervical muscle hypoplasia, hearing loss, and mild intellectual disabilities. Additional findings include vertebral anomalies and short stature.
Spondyloepimetaphyseal dysplasia-short limb-abnormal calcification syndrome is a rare genetic disorder which is characterized by osseous anomalies resulting in short stature and other afflictions.
Schneckenbecken dysplasia is a rare pre-natally fatal hereditary autosomal recessive condition which affects the bones and pre-natal growth.
Syndactyly-nystagmus syndrome due to 2q31.1 microduplication, also known as 2q31.1 microduplication syndrome, is a rare genetic disorder characterized by syndactyly affecting the third-fourth fingers and bilateral congenital nystagmus.
Hall-Riggs syndrome is a rare genetic disorder that causes neurological issues and birth defects. People with Hall-Riggs syndrome usually have skeletal dysplasia, facial deformities, and intellectual disabilities. Only 8 cases from 2 families worldwide have been described in medical literature. It is an autosomal recessive genetic disorder, meaning both parents must carry the gene in order for their offspring to be affected.
Ventricular extrasystoles with syncopal episodes-perodactyly-Robin sequence syndrome is a rare autosomal dominant genetic disorder characterized by cardiofaciodigital anomalies occurring alongside Pierre Robin sequence. Additional features include abnormal sense of smell, camptodactyly, recurrent joint dislocations, and short stature. Around 6 to 12 cases have been described in medical literature.
Calvarial doughnut lesions-bone fragility syndrome, also known as familial calvarial doughnut lesions, is a rare autosomal dominant genetic disorder characterized by mild to moderate fragility of the bones accompanied with calvarial doughnut lesions.
SOFT syndrome, also known for the name its acronym originates from: Short stature-onychodysplasia-facial dysmorphism-hypotrichosis syndrome, is a rare genetic disorder characterized by the presence of short stature, underdeveloped nails, facial dysmorphisms, and hair sparcity across the body. It is caused by homozygous, autosomal recessive mutations in the POC1A gene, located in the short arm of chromosome 3. Fewer than 15 cases have been described in the medical literature.
Spondyloenchondrodysplasia is the medical term for a rare spectrum of symptoms that are inherited following an autosomal recessive inheritance pattern. Skeletal anomalies are the usual symptoms of the disorder, although its phenotypical nature is highly variable among patients with the condition, including symptoms such as muscle spasticity or thrombocytopenia purpura. It is a type of immunoosseous dysplasia.