Diversity, parental germline origin, and phenotypic spectrum of de novo HRAS missense changes in Costello syndrome.
Activating mutations in v-Ha-ras Harvey rat sarcoma viral oncogene homolog (HRAS) have recently been identified as the molecular cause underlying Costello syndrome (CS). To further investigate the phenotypic spectrum associated with germline HRAS mutations and characterize their molecular diversity, subjects with a diagnosis of CS (N = 9), Noonan syndrome (NS; N = 36), cardiofaciocutaneous syndrome (CFCS; N = 4), or with a phenotype suggestive of these conditions but without a definitive diagnosis (N = 12) were screened for the entire coding sequence of the gene. A de novo heterozygous HRAS change was detected in all the subjects diagnosed with CS, while no lesion was observed with any of the other phenotypes. While eight cases shared the recurrent c.34G>A change, a novel c.436G>A transition was observed in one individual. The latter affected residue, p.Ala146, which contributes to guanosine triphosphate (GTP)/guanosine diphosphate (GDP) binding, defining a novel class of activating HRAS lesions that perturb development. Clinical characterization indicated that p.Gly12Ser was associated with a homogeneous phenotype. By analyzing the genomic region flanking the HRAS mutations, we traced the parental origin of lesions in nine informative families and demonstrated that de novo mutations were inherited from the father in all cases. We noted an advanced age at conception in unaffected fathers transmitting the mutation.
Zampino
Giuseppe
G
Istituto di Clinica Pediatrica, Università Cattolica del Sacro Cuore, Rome, Italy.
Pantaleoni
Francesca
F
Carta
Claudio
C
Cobellis
Gilda
G
Vasta
Isabella
I
Neri
Cinzia
C
Pogna
Edgar A
EA
De Feo
Emma
E
Delogu
Angelica
A
Sarkozy
Anna
A
Atzeri
Francesca
F
Selicorni
Angelo
A
Rauen
Katherine A
KA
Cytrynbaum
Cheryl S
CS
Weksberg
Rosanna
R
Dallapiccola
Bruno
B
Ballabio
Andrea
A
Gelb
Bruce D
BD
Neri
Giovanni
G
Tartaglia
Marco
M
D000015:Abnormalities, Multiple / Q000235:genetics; D000328:Adult; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005260:Female; D011905:Genes, ras; D005820:Genetic Testing; D014644:Genetic Variation; D018095:Germ-Line Mutation; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008958:Models, Molecular; D020125:Mutation, Missense; D010290:Parents; D010375:Pedigree; D010641:Phenotype; D013577:Syndrome