Ciliopathies
Gene: HYLS1
A recurring homozygous missense variant p.Asp211Gly has been identified in at least 64 cases of hydrolethalus syndrome, described as a Finnish founder mutation (PMID: 15843405, PMID: 18648327). Functional studies in human and patient cells have shown mislocalisation of the protein to the nucleus (PMID: 15843405, PMID: 19400947). Functional studies in c. elegans showed that this variant impaired ciliogenesis (PMID: 19656802). Functional studies in drosophila showed that deletion of HYLS1 led to cilia dysfunction (PMID: 32509774). 2 homozygous living siblings (stop-loss, extension variant p.Ter300TyrextTer11) both diagnosed with Joubert syndrome. Patients had molar tooth signs and dysplasia of cerebellar vermis (PMID: 26830932). No other variants have been reported as pathogenic in this gene.
Green rating given at least two variants reported with a ciliopathy phenotype and supporting functional data from multiple animal models all indicative of ciliopathy.Created: 6 Aug 2020, 11:44 p.m. | Last Modified: 6 Aug 2020, 11:44 p.m.
Panel Version: 0.198
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Hydrolethalus syndrome (MIM#236680)
Publications
OMIM notes Dandy Walker anomaly as a neurological feature. All patients results in either stillbirths or neonatal death, so limited information available. Almost all patients have the same recurring missense (p.Asp211Gly)
PMID: 18648327 - describes many patients with the recurring missense mutation. Summary table describes brain features of 19 patients, none appear to be consistent with JS
PMID: 26830932 - 2 homozygous living siblings (stop-loss, extension) both diagnosed with JS. Patients had molar tooth signs and dysplasia of cerebellar vermis
Single reported family, but likely due to a unique mutational spectrum separate from the recurring missense
Sources: Expert listCreated: 13 May 2020, 2:26 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Hydrolethalus syndrome 236680
Publications
Publications for gene: HYLS1 were set to 15843405; 18648327; 19400947; 19656802; 32509774
Gene: hyls1 has been classified as Green List (High Evidence).
Phenotypes for gene: HYLS1 were changed from to Hydrolethalus syndrome (MIM#236680)
Publications for gene: HYLS1 were set to
Mode of inheritance for gene: HYLS1 was changed from Unknown to BIALLELIC, autosomal or pseudoautosomal
Tag founder tag was added to gene: HYLS1.
gene: HYLS1 was added gene: HYLS1 was added to Ciliopathies_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services Mode of inheritance for gene: HYLS1 was set to Unknown