Girl-Boy Twins with Developmental Delay from 16p11.2 Triplication due to Biparental Inheritance from Two Parents with...

Area of Science:

• Genetics
• Developmental Biology
• Clinical Medicine

Background:

• The 16p11.2 duplication syndrome is a recognized genetic cause of neurodevelopmental disorders, including developmental delay and autism spectrum disorder.
• 16p11.2 triplication is exceedingly rare, with only two prior cases documented, both involving tandem triplication inherited from a single parent.

Observation:

• This study reports on fraternal twins diagnosed with developmental delay and 16p11.2 triplication.
• The twins inherited a duplicated 16p11.2 region from each parent, a distinct inheritance pattern from previously reported cases.

Findings:

• The fraternal twins presented with developmental delay and a unique inheritance pattern of 16p11.2 triplication, receiving duplicated homologs from both parents.
• This contrasts with the two previously reported cases, which involved tandem triplication inherited from only one parent.

Implications:

• This case expands the known inheritance patterns of 16p11.2 triplication.
• Understanding these varied genetic mechanisms is crucial for accurate diagnosis and genetic counseling in families with neurodevelopmental disorders.
• Further research into the phenotypic spectrum and genetic underpinnings of 16p11.2 triplication is warranted.