Cooks syndrome

Cooks syndrome (also known as nail hypoplasia/absence with brachydactyly type B and duplicated thumbs) is an extremely rare genetic disorder primarily affecting the development of the nails and bones of the hands and feet. The condition is characterized by anonychia or severe nail hypoplasia (absence or underdevelopment of fingernails and toenails), brachydactyly type B (shortening of the fingers and toes, particularly affecting the distal phalanges), and bilateral duplication (bifurcation) of the distal phalanx of the thumbs and halluces (big toes). The skeletal abnormalities predominantly involve the terminal phalanges, which may be absent or hypoplastic, leading to shortened digits. The nail changes are most prominent on the fingers and toes where the underlying bone is affected. Cooks syndrome is caused by heterozygous mutations in the FBXW4 gene (also known as DAC), located on chromosome 10q24. This gene plays a role in limb development, and disruptions in its function or regulation lead to the characteristic digital anomalies seen in this condition. The syndrome was first described by Cooks and colleagues in 1985 in a large South African family. There is currently no cure or specific treatment for Cooks syndrome. Management is supportive and symptomatic, focusing on orthopedic evaluation and potential surgical intervention for significant digital malformations if they impair hand or foot function. Genetic counseling is recommended for affected individuals and their families. The condition does not typically affect intellectual development or internal organs, and life expectancy is generally normal.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Cooks syndrome