SNP Shot: Genomic Insights

DNMT3A overgrowth syndrome is a condition distinguished by accelerated growth both before and after birth, slight variations in facial features, and intellectual disability.

Those with DNMT3A overgrowth syndrome tend to be longer than average at birth and maintain a taller stature compared to others throughout their lives. Many affected individuals experience weight gain during late childhood or adolescence and may also exhibit an unusually large head size (macrocephaly).

The typical facial features associated with DNMT3A overgrowth syndrome include a rounded face, prominent horizontal eyebrows, and reduced eye opening width (narrowed palpebral fissures). Furthermore, the upper front teeth are frequently larger than usual.

The severity of intellectual disability in DNMT3A overgrowth syndrome varies from mild to severe. Individuals may also display characteristics of autism spectrum disorder, involving difficulties with communication and social interaction.

Additional signs and symptoms that can occur in individuals with DNMT3A overgrowth syndrome include an abnormally curved spine (kyphoscoliosis), heart abnormalities, flat feet (pes planus), low muscle tone (hypotonia), or unusually flexible joints (hypermobile joints). Psychological conditions like depression, anxiety, or obsessive-compulsive disorder may also be present.

Inheritance:

This condition follows an autosomal dominant inheritance pattern, meaning that only one copy of the mutated gene in each cell is enough to cause the disorder. In some instances, the affected individual inherits the mutated gene from a parent who also has the condition. However, in other instances, the condition arises from a new gene mutation, occurring in individuals with no prior family history of the disorder.