Novel SMAD4 mutation causing Myhre syndrome.
Myhre syndrome (MYHRS, OMIM 139210) is an autosomal dominant disorder characterized by developmental and growth delay, athletic muscular built, variable cognitive deficits, skeletal anomalies, stiffness of joints, distinctive facial gestalt and deafness. Recently, SMAD4 (OMIM 600993) was identified by exome sequencing as the disease gene mutated in MYHRS. Previously only three missense mutations affecting Ile500 (p.Ile500Thr, p.Ile500Val, and p.Ile500Met) have been described in 22 unrelated subjects with MYHRS or a clinically related phenotype. Here we report on a 15-year-old boy with typical MYHRS and a novel heterozygous SMAD4 missense mutation affecting residue Arg496. This finding provides further information about the distinctive SMAD4 mutation spectrum in MYHRS. In silico structural analyses exploring the impact of the Arg-to-Cys change at codon 496 suggested that conformational changes promoted by replacement of Arg496 impact the stability of the SMAD heterotrimer and/or proper SMAD4 ubiquitination.
Dipartimento di Medicina Sperimentale, Sapienza Università di Roma, Rome, Italy.
Viviana
V
Caputo
Gianfranco
G
Bocchinfuso
Marco
M
Castori
Alice
A
Traversa
Antonio
A
Pizzuti
Lorenzo
L
Stella
Paola
P
Grammatico
Marco
M
Tartaglia
D002675:Child, Preschool; D003062:Codon; D003456:Cryptorchidism / Q000175:diagnosis* / Q000235:genetics*; D019066:Facies; D056726:Genetic Association Studies; D006130:Growth Disorders / Q000175:diagnosis* / Q000235:genetics*; D006228:Hand Deformities, Congenital / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D006984:Hypertrophy / Q000175:diagnosis* / Q000235:genetics*; D008607:Intellectual Disability / Q000175:diagnosis* / Q000235:genetics*; D007592:Joint Diseases / Q000175:diagnosis* / Q000235:genetics*; D008297:Male; D008958:Models, Molecular; D009154:Mutation; D010641:Phenotype; D011487:Protein Conformation; D055503:Protein Multimerization; D055550:Protein Stability; D017422:Sequence Analysis, DNA; D051901:Smad4 Protein / Q000737:chemistry / Q000235:genetics*
D003062:Codon; D051901:Smad4 Protein
Myhre syndrome; SMAD4; TGF-β pathway; mutation analysis; structural analyses