SNP Shot: Genomic Insights

Adams-Oliver syndrome is a rare congenital disorder, meaning it is present at birth. Its main characteristics include skin abnormalities, specifically aplasia cutis congenita, and limb malformations. Individuals with Adams-Oliver syndrome may also experience a range of other symptoms.

Aplasia cutis congenita, a defining feature of Adams-Oliver syndrome, involves localized areas where skin is missing. This commonly occurs on the top of the head (skull vertex). In some instances, the underlying bone may also be underdeveloped. Affected areas often exhibit scarring and a lack of hair growth.

Hand and foot abnormalities are also prevalent in individuals with Adams-Oliver syndrome. These often involve the fingers and toes and can manifest as abnormal nails, fused fingers or toes (syndactyly), or abnormally short or missing fingers or toes (brachydactyly or oligodactyly). In some cases, bones in the hands, feet, or lower limbs may be malformed or absent.

Some infants with Adams-Oliver syndrome may present with cutis marmorata telangiectatica congenita, a blood vessel disorder causing a reddish or purplish net-like pattern on the skin. Furthermore, affected individuals can develop pulmonary hypertension, a dangerous condition involving high blood pressure in the vessels between the heart and lungs. Other cardiovascular issues and heart defects may also occur.

Neurological problems can sometimes occur in individuals with Adams-Oliver syndrome, including developmental delays, learning disabilities, or structural brain abnormalities.

Inheritance:

Adams-Oliver syndrome can be inherited in different ways. When caused by mutations in the ARHGAP31, DLL4, NOTCH1, or RBPJ genes, it follows an autosomal dominant inheritance pattern. This means that only one copy of the altered gene in each cell is enough to cause the condition. Typically, the altered gene is passed down from an affected parent. However, some cases linked to NOTCH1 gene mutations arise from new (de novo) mutations during the formation of reproductive cells (eggs or sperm) or in early embryonic development, occurring in individuals without a family history of the disorder. When mutations occur in the DOCK6 or EOGT genes, Adams-Oliver syndrome is inherited in an autosomal recessive manner. In this pattern, both copies of the gene in each cell must have mutations for the condition to develop. Parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not exhibit symptoms of the condition.