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). 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 Ancient and noble French family names, Jacques, Jacq, or James are believed to originate from the Middle Ages in the historic northwest Brittany region in France, and have since spread around the world over the centuries. To date, there are over ...

, physician in Lilles, France, and colleagues as "familial pelvi-scapular dysplasia with dwarfism and dysmorphisms". 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 Andrea Superti-Furga (born 1959 in Milan) 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 Medicin ...

showed that the condition was caused by biallelic inactivating variants in the gene coding for the T-box transcription factor, TBX15. 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. An important differential diagnosis in the newborn and infant is

campomelic dysplasia 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 ...

, 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 Transcription factor SOX-9 is a protein that in humans is encoded by the ''SOX9'' gene. Function SOX-9 recognizes the sequence CCTTGAG along with other members of the HMG-box class DNA-binding proteins. It is expressed by proliferating but no ...

gene, is less rare than Cousin syndrome.Unger S, Scherer G, Superti-Furga A. Campomelic Dysplasia. 2008 Jul 31 pdated 2021 Mar 18 In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® nternet Seattle (WA): University of Washington, Seattle; 1993-2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1760/

References

Genetic diseases and disorders {{Genetic-disorder-stub