Mutations in HIVEP2 are associated with developmental delay, intellectual disability, and dysmorphic features

Original research article by H. Steinfeld et al. (2016)

Read the article here.

This article looks at the specific effects of damaging changes in the HIVEP2 gene. Previous studies of HIVEP2 changes have documented intellectual disability and developmental delay in three people. This study describes the behavioral, medical, and developmental features of six children who have changes in HIVEP2. The children received a complete medical evaluation, including whole-exome sequencing, MRI, and physical examination. The following features were documented:

• All six children had developmental delay, intellectual disability, and mild dysmorphic features.
• Autism, hyperactivity, anxiety, and oppositional behaviors were common.
• Two of the children, ages 10 and 14 years, were nonverbal. One child, age 2, spoke only three words. One child, age 6, spoke only three- to four-word sentences, and another, age 11, spoke in full sentences
• IQ ranged from 50 to 75.
• Two of the children had seizures.
• Four had low muscle tone, and one had increased muscle tone on arms and legs.
• Three of the children had decreased head size and brain size.
• Gastrointestinal issues of constipation and gastroesophageal reflux disease were reported.
• Eye issues, including strabismus, in which the eyes do not point in the same direction, and amblyopia, or “lazy eye,” were reported in three children.

Overall, the features that have been seen in all nine people (six from this study and three from the literature) are developmental delay, intellectual disability, and dysmorphic features.