Early onset or syndromic epilepsy

Gene: MMADHC

Green List (high evidence)

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Homocystinuria, cblD type, variant 1 277410; Methylmalonic aciduria and homocystinuria, cblD type, 277410; Methylmalonic aciduria, cblD type, variant 2, 277410

Publications

• 18385497

I don't know

Review and rating collated by Tracy Lester (Oxford Medical Genetics Laboratories Oxford University Hospitals NHS Foundation Trust, 2019_02_06) on behalf of Wessex and West Midlands GLH for GMS Neurology specialist test group, for Clinical Indication R59 'Early onset or syndromic epilepsy'. Review contributors: John Taylor. Suggested gene rating: Green.

Created: 6 Aug 2019, 8:38 p.m. | Last Modified: 6 Aug 2019, 8:38 p.m.

Panel Version: 1.189

Comment on list classification: Updated rating from Amber to Green. Green rating by Zornitza, and sufficient unrelated cases of patients with MMADHC variants and seizures (4 cases in PMID:18385497) for inclusion on panel.

Created: 3 Dec 2018, 1:10 p.m.

Coelho et al. (2008, PMID:18385497) studied 7 unrelated patients with cblD defect, either isolated homocystinuria, isolated methylmalonic aciduria or a combined phenotype. Seizures were seen in 4 patients: Patient 2 (Italian boy), 3 (Indian boy with neonatal convulsions), 6 (Scandinavian girl) and 7 (Italian boy). All these patients had compound het or homozygous variants in MMADHC. Patients were either unique to this study or previously described.

Created: 3 Dec 2018, 1:02 p.m.

Green List (high evidence)

Seizures are part of the phenotype of this metabolic disorder.

Created: 16 Aug 2018, 12:08 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Methylmalonic aciduria and homocystinuria, cblD type, MIM#277410

Variants in this GENE are reported as part of current diagnostic practice