Cardiomyopathy_Paediatric
Gene: STX4
PMID 35599850: two unrelated families were identified with biallelic STX4 variants: Family 1 with a homozygous missense c.718C>T (p.Arg240Trp) and Family 2 compound heterozygous c.89_90delGC (p.Gly30Aspfs*28) and c.232+4A>C (splice‑site). Affected individuals present with early‑onset dilated cardiomyopathy, ventricular arrhythmia, sensorineural hearing loss, global developmental delay, hypotonia and multiple congenital anomalies; the second individual died perinatally. CRISPR‑generated stx4‑null zebrafish recapitulate cardiac dysfunction, bradycardia, reduced vesicle docking and altered Ca²⁺ handling. Transgenic rescue with wild‑type stx4 restores phenotype, whereas the R241W (human R240W) allele is hypomorphic and only partially rescues, supporting a loss‑of‑function mechanism. Pharmacologic L‑type Ca²⁺ channel modulation ameliorated bradycardia, further underscoring functional loss of STX4.
Unclear if this is a separate disease association or whether it will be part of a spectrum with the previous isolated deafness reports.Created: 6 Mar 2026, 3 p.m. | Last Modified: 6 Mar 2026, 3 p.m.
Panel Version: 1.331
PMID:36355422 reported a large consanguineous Pakistani family with eight affected individuals showing bilateral severe-to-profound hearing impairment. A homozygous splice region variant was identified in STX4 (c.232 + 6T>C), which causes exon skipping and a frameshift, that segregated with hearing impairment in this family. In silico analysis showed that murine Stx4a is highly and widespread expressed in the developing and adult inner ear. Knockdown of stx4 in zebrafish showed an abnormal startle response, morphological and developmental defects, and a disrupted mechanotransduction function in neuromast hair cells.
Sources: LiteratureCreated: 24 Mar 2023, 2:07 p.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Non-syndromic genetic hearing loss, MONDO:0019497, STX4-related
Publications
Gene: stx4 has been classified as Amber List (Moderate Evidence).
gene: STX4 was added gene: STX4 was added to Cardiomyopathy_Paediatric. Sources: Expert Review Amber,Literature,Literature Mode of inheritance for gene: STX4 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: STX4 were set to 36355422; 35599850 Phenotypes for gene: STX4 were set to Deafness, autosomal recessive 123, MIM# 620745