Pseudohypoparathyroidism and Albright Hereditary Osteodystrophy
Gene: STX16
Multiple reports of a PHP-Ib phenotype.
Caused in most cases by a maternally inherited 3-kb, 4.4-kb or larger deletion involving STX16, which is associated with loss of methylation (LOM) at GNAS exon A/B DMR (also referred to as exon 1A or GNAS A/B:TSS-DMR).
Of PHP1B cases, 15–20% are familial, with an autosomal dominant mode of inheritance (AD-PHP1B) through the maternal lineage. In this familial form, the methylation defect is usually limited to loss of methylation at GNAS A/B:TSS-DMR, secondary to a 3 kb microdeletion on the maternal allele of cis-acting control elements within STX16. Other maternally inherited deletions and duplications have also been identified in some rare familial cases affecting either an isolated GNAS A/B:TSS-DMR or all four DMRs (Nature review, PMID 29959430)
STX16 is not clearly an imprinted gene, but only maternally inherited deletions are associated with this phenotype. Deletions in this gene are thought to disrupt cis-acting regulation of GNAS expression.Created: 20 Oct 2021, 7:24 p.m. | Last Modified: 20 Oct 2021, 7:24 p.m.
Panel Version: 0.4
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, paternally imprinted (maternal allele expressed)
Phenotypes
Pseudohypoparathyroidism type 1b MIM#: 603233
Publications
Gene: stx16 has been classified as Green List (High Evidence).
Phenotypes for gene: STX16 were changed from to Pseudohypoparathyroidism type 1b MIM#: 603233
Publications for gene: STX16 were set to
Mode of inheritance for gene: STX16 was changed from Unknown to MONOALLELIC, autosomal or pseudoautosomal, paternally imprinted (maternal allele expressed)
Tag SV/CNV tag was added to gene: STX16.
gene: STX16 was added gene: STX16 was added to Pseudohypoparathyroidism, Albright Hereditary Osteodystrophy_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services Mode of inheritance for gene: STX16 was set to Unknown