SNP Shot: Genomic Insights

Popliteal pterygium syndrome is a genetic disorder impacting facial, skin, and genital development. A frequent characteristic of this syndrome is the presence of a cleft lip, a cleft palate (an opening in the roof of the mouth), or both at birth. Individuals affected by this condition might also have small depressions, or pits, on the lower lip that often appear moist due to the presence of salivary glands within the pits. Small tissue mounds can also form on the lower lip. Tooth agenesis (missing teeth) is observed in some individuals.

Webbing of the skin behind the knees is a common feature, which can restrict movement if left untreated. Other manifestations include webbing or fusion of the digits (syndactyly), distinctive triangular skin folds near the toenails of the big toes, and tissue connecting the eyelids or jaws. Genital abnormalities can also occur, such as underdeveloped outer labia (hypoplasia of the labia majora) in females. In males, these abnormalities may present as undescended testicles (cryptorchidism) or a scrotum split into two sections (bifid scrotum).

Similar to other individuals with cleft lip and/or palate, those with popliteal pterygium syndrome and these facial anomalies may face an elevated risk of delayed language skills, learning disabilities, or subtle cognitive difficulties. However, the average intelligence quotient (IQ) of individuals with popliteal pterygium syndrome is generally within the normal range of the general population.

Inheritance:

Popliteal pterygium syndrome follows an autosomal dominant inheritance pattern. This means that the presence of a single copy of the mutated gene in each cell is enough to cause the condition.