Severe microcephaly

Gene: TTI1

Green List (high evidence)

Comment on phenotypes: Relevant phenotype now listed in OMIM (Neurodevelopmental disorder with microcephaly and movement abnormalities, OMIM:620445)

Created: 2 May 2024, 1:19 p.m. | Last Modified: 2 May 2024, 1:19 p.m.

Panel Version: 5.6

The rating of this gene has been updated to Green and the mode of inheritance set to 'BIALLELIC, autosomal or pseudoautosomal' following NHS Genomic Medicine Service approval.

Created: 2 May 2024, 1:14 p.m. | Last Modified: 2 May 2024, 1:14 p.m.

Panel Version: 5.4

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Green List (high evidence)

Comment on list classification: There is enough evidence for this gene to be rated GREEN at the next major review.

Created: 14 Jun 2023, 9:32 a.m. | Last Modified: 14 Jun 2023, 9:32 a.m.

Panel Version: 4.27

TTI1 has not previously been associated with a phenotype in OMIM, Gen2Phen or MONDO. At least 2 variants have been reported. PMID: 36724785 reported 15 TTI1 variants as either homozygotes (2 families) or compound heterozygotes (7 families) in cases with a neurodevelopmental disorder with microcephaly. In all cases the parents were heterozygous carriers of the TTI1 variant identified in the affected child. Development delay was observed in all of the families (9/9), moderate to severe intellectual disability was evident in all families where it could be assessed (8/8) and severe microcephaly was present in members of 5/9 families. Supportive functional results were also presented.
Sources: Literature

Created: 14 Jun 2023, 9:24 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
neurodevelopmental disorder with microcephaly

Publications

• 36724785