McKusick-Kaufman syndrome is a condition that affects the development of the hands, feet, heart, and reproductive system. It is characterized by a combination of three features: extra fingers and/or toes (polydactyly), congenital heart defects, and genital abnormalities. The most common genital abnormality is hydrometrocolpos, an accumulation of fluid in the vagina and uterus.

Some variants (also called mutations) in the MKKS gene have been found to cause McKusick-Kaufman syndrome. The MKKS gene is also called the BBS6 gene. This gene provides instructions for making a protein that plays an important role in early development, specifically in the formation of the limbs, heart, and reproductive system. The protein's structure suggests that it may belong to a family of proteins called chaperonins. Proteins must be folded into the correct shape to function properly, and chaperonins help them do that.

More than 100 individuals with McKusick-Kaufman syndrome have been reported in the literature. This condition was first described in the Old Order Amish population, where it affects an estimated 1 in 10,000 people.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell must have a variant that causes the disorder. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition.

Published Date: April 16, 2024
Published By: National Institutes of Health