SNP Shot: Genomic Insights

HIVEP2-related intellectual disability is a neurological condition marked by developmental delays ranging from moderate to severe, intellectual disability, and subtle physical differences (dysmorphic features). Individuals with this condition often exhibit early signs such as low muscle tone (hypotonia) and delays in achieving motor milestones like sitting, standing, and walking. Even after learning to walk, many continue to experience difficulties, displaying an unsteady, wide-based gait. Speech development is also typically delayed, and some individuals may never develop verbal communication skills. Commonly observed physical traits include widely spaced eyes (hypertelorism) and a wide nasal bridge, or tapered fingers. However, the specific combination of these features varies among affected individuals. Many individuals also present with neurodevelopmental conditions like hyperactivity, attention deficit disorder, aggression, anxiety, and autism spectrum disorder, which encompasses a range of developmental disorders impacting communication and social skills.

Additional features associated with HIVEP2-related intellectual disability can include minor structural brain abnormalities and an unusually small brain and head size (microcephaly). Less frequently, individuals may experience seizures, recurrent ear infections, or eye problems such as crossed eyes (strabismus), amblyopia ("lazy eye"), or farsightedness (hyperopia). Some individuals also suffer from gastrointestinal issues, including gastroesophageal reflux (backflow of stomach acid into the esophagus) and constipation.

Inheritance:

The inheritance pattern for this condition is autosomal dominant. This means that only one copy of the mutated gene in each cell is enough to cause the disorder. In most instances, the condition arises from new (de novo) mutations in the HIVEP2 gene. These mutations typically occur during the creation of reproductive cells (egg or sperm) in a parent of the affected individual or during the early stages of embryonic development. Consequently, these cases often appear in individuals with no family history of the disorder.