Families

THG1L-related disorder is characterized by motor developmental delays, impaired balance and coordination, and a specific brain abnormality called cerebellar vermis hypoplasia. Many individuals have normal/ near normal intelligence. More severe features have also been reported, which include seizures, smaller than expected head (microcephaly), profound intellectual disability, and brain abnormalities called brain atrophy and cerebellar hypoplasia.

THG1L-related disorder is rare and has been reported in less than 15 individuals in the medical literature. The condition is inherited in an autosomal recessive pattern, which means that an individual needs a mutation in both copies of the gene in order to have the condition. Individuals with only one mutation are called carriers and are not expected to exhibit symptoms. Correlation between specific variants and the resulting symptoms has been described.