A novel UBE2A splice site variant causing intellectual disability type Nascimento

Area of Science:

• Genetics
• Neurodevelopmental Disorders
• Rare Diseases

Background:

• X-linked intellectual disability type Nascimento (XLID) is a rare genetic disorder.
• It is caused by variants in the ubiquitin-conjugating enzyme E2A gene (UBE2A).
• Previously, only two splice-site variants in UBE2A have been reported in XLID patients.

Observation:

• A Chinese boy presented with clinical features similar to XLID, including speech impairment, severe intellectual disability, and hearing loss.
• Unique features included an inability to maintain an upright head posture and a single transverse palmar crease on both palms.
• Whole-exome sequencing was performed.

Findings:

• A novel splice site variant, c.241+1 G>A, was identified in the UBE2A gene.
• This variant is associated with the patient's observed phenotype.
• This discovery broadens the spectrum of UBE2A variants.

Implications:

• The study expands the known clinical characteristics associated with UBE2A deficiency syndrome.
• It provides further evidence for the genetic basis of XLID-like phenotypes.
• This research aids in the genetic diagnosis of similar conditions.