Congenital Heart Defect
Gene: SMAD5
SMAD5 encodes a transcriptional regulator that functions within the TGF-b signalling cascade. Animal studies show this protein is crucial for dorsoventral patterning, left/right asymmetry, cardiac looping.
7 affected individuals from 6 families described in PMID: 40619738 with congenital heart disease (ASD, VSD, hypoplastic left heart). 4 cases had de novo variants in SMAD5 with some cases having inheritance from presumably unaffected parents (however parents weren't formally assessed). All variants absent from gnomAD v4.
Supportive functional studies with transfection of variants into HEK293T cells showing reduced SMAD5 levels and luciferase promoter assay showing reduced promoter activity of downstream targets with rescue upon introduction of WT SMAD5. LOF mechanism proposed. Variants were missense/nonsense/frameshift/large del.
One individual presented with a more severe multi system phenotype including tetralogy of fallot, craniofacial/urogenital/renal/limb/vertebral anomalies with a variant that was proposed to act in a dominant negative manner. NM_005903.7(SMAD5):c.1289C>T|p.Thr430Ile. Functional studies performed supported this proposed mechanism.
Sources: LiteratureCreated: 5 Aug 2025, 6:38 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Congenital heart disease, MONDO:0005453, SMAD5-related
Publications
Gene: smad5 has been classified as Green List (High Evidence).
Gene: smad5 has been classified as Green List (High Evidence).
gene: SMAD5 was added gene: SMAD5 was added to Congenital Heart Defect. Sources: Literature Mode of inheritance for gene: SMAD5 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: SMAD5 were set to PMID: 40619738 Phenotypes for gene: SMAD5 were set to Congenital heart disease, MONDO:0005453, SMAD5-related Penetrance for gene: SMAD5 were set to Incomplete Review for gene: SMAD5 was set to GREEN