Rebecca Foulger commented on gene: ASAH1: The Green rating by Dr Alisdair McNeil (Sheffield Children's Hospital, Yorkshire and North East GLH) supports the current Green rating of ASAH1.
Rebecca Foulger Phenotypes for gene: ASAH1 were changed from Spinal muscular atrophy with progressive myoclonic epilepsy, 159950 to Spinal muscular atrophy with progressive myoclonic epilepsy, 159950; SMA with myoclonic epilepsy
alisdair mcneill reviewed gene: ASAH1: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: SMA with myoclonic epilepsy; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Rebecca Foulger edited their review of gene: ASAH1: Added comment: 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 and Helen Lord. Suggested gene rating: Green. ; Changed rating: AMBER
Rebecca Foulger Added comment: Comment on list classification: Updated rating from Red to Green. Confirmed Disease confidence rating in Gene2Phenotype for SPINAL MUSCULAR ATROPHY ASSOCIATED WITH PROGRESSIVE MYOCLONIC EPILEPSY. Relevant disorder in OMIM (Spinal muscular atrophy with progressive myoclonic epilepsy, 159950). Although the three families reported in PMID:22703880 share a haplotype suggesting Founder effect, there are sufficient additional papers reporting cases with additional variants. Note that although most individuals report muscle weakness followed by seizures, PMIDs 27026573 and 30291339 report muscle weakness WITHOUT epilepsy, and PMID:24164096 also report a case with seizures without muscle weakness- there is therefore some heterogeneity in the phenotype. On balance there are plenty of literature reports of seizures in patients with biallelic ASAH1 variants for inclusion on this panel.
Rebecca Foulger commented on gene: ASAH1: Additional cases of seizures associated with SMA were reported in papers including PMIDs 27723502, 26526000, 25847462, 25578555, 31216804.
Rebecca Foulger commented on gene: ASAH1: PMID:27723502 (Oguz et al, 2016) report eyelid myoclonic status epilepticus as an unusual manifestation of SMA-PME in a Turkish girl of consanguineous parents. Ambulatory problems were noted age 4. Generalized seizures developed later.
Rebecca Foulger commented on gene: ASAH1: PMID:29169047: Yidiz et al (2018) report a 13.5 yr old girl with SMA-PME. She was the 8th child born of consanguineous parents. She presented with progressive muscle weakiness age 10, tremor, seizure (generalized epilepsy) and decreased cognitive functions. Screening revelead homozygous missense variant c.173C>T (T58M). The parents or siblings were not tested.
Rebecca Foulger changed review comment from: PMID:30291339: Ame van der Beek et al (2019) report an additional case of a mild SMA phenotype with NO myoclonic epilepsy due to variants in ASAH1. Ambulatory problems of the 24 year old female began around age 8 years.; to: PMID:30291339: Ame van der Beek et al (2019) report an additional case of a mild SMA phenotype with NO myoclonic epilepsy due to variants in ASAH1. She carried two novel ASAH1 variants (Pro26Arg and c.125+1G>A splice variant leading to an unstable transcript lacking exon 2. Segregation analysis confirmed the parental inheritance and acid ceramidase activity was deficient in functional tests.
Rebecca Foulger commented on gene: ASAH1: PMID:30291339: Ame van der Beek et al (2019) report an additional case of a mild SMA phenotype with NO myoclonic epilepsy due to variants in ASAH1. Ambulatory problems of the 24 year old female began around age 8 years.
Rebecca Foulger commented on gene: ASAH1: PMID:27026573: Filosto et al., 2016 studied 2 subjects: a 30yr old pregnant woman and her 17 year old sister affected with slowly progressive SMA since childhood but in the ABSENCE of siezures. Both subjects had a homozygous c.124A>G (T42A) variant in ASAH1.
Rebecca Foulger commented on gene: ASAH1: PMID:24164096: In a girl who presented with absence and atonic seizures age 10, Dyment et al. (2014) identified compound heterozygous mutations in the ASAH1 gene: c.850G>T (G284X) and c.456A>C. Each parent was found to carry one of the variants. Although c.456A>C is predicted to encode a Lys152Asn substitution, it is 2bp away from a splice donor site and fibroblast assays showed an absence of exon 6, suggesting abberant splicing. Note that the patient harboured several hundred rare variants with at least two rare non-synonymous variants within the coding sequence of 4 genes (ASAH1, OC90, CACNA1C and LAMA5) though CACNA1C and OC90 were ruled out because the variants were found to be inherited from a single parent. Unlike the cases from PMID:22703880, this patient presented with seizures as the first symptom, and displayed no significant muscle weakness.