Autosomal recessive
Caused by changes in both copies of THOC6, part of the TREX complex that exports messenger RNA from the nucleus. A founder variant has been described in the Hutterite community.
Signs and symptoms
Developmental delay and intellectual disability, from mild to severe, are typical, along with small head size and distinctive facial features. Congenital heart defects and kidney differences occur in some. Dental anomalies and genital differences are common, and seizures occur less often.
What a diagnosis changes
Heart and kidney assessment at diagnosis, with developmental and educational support. Genetic counselling and carrier testing of relatives clarify recurrence risk, particularly in communities where the founder variant has been described.
Genes analysed
Also known as
BBIS; BEAULIEU-BOYCOTT-Innes syndrome; microcephaly, mental retardation, and distinctive facies, with Cardiac and genitourinary malformations
