Early onset or syndromic epilepsy
Gene: MMADHC
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
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.
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
Source Wessex and West Midlands GLH was added to MMADHC.
Source NHS GMS was added to MMADHC.
Zornitza Stark: Seizures are part of the pheno
Gene: mmadhc has been classified as Green List (High Evidence).
Gene: mmadhc has been classified as Green List (High Evidence).
Mode of inheritance for gene: MMADHC was changed from to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: MMADHC were changed from to Methylmalonic aciduria and homocystinuria, cblD type, 277410
Expert Review Amber was added to MMADHC. Panel: Genetic Epilepsy Syndromes
MMADHC was added to Genetic Epilepsy Syndromes panel. Sources: Victorian Clinical Genetics Services
MMADHC was created by Sarah Leigh