and variants in a boy with ambiguous genitalia, short stature, and non-specific dysmorphic features.

Noonan syndrome is a congenital disorder characterized by distinctive facial appearance, congenital heart defects, short stature, and skeletal dysplasia. Although boys with Noonan syndrome frequently exhibit cryptorchidism, a mild form of 46,XY disorders of sex development (DSD), they barely manifest more severe genital abnormalities. Here, we report a boy with ambiguous genitalia, short stature, and non-specific dysmorphic features. He had no cardiac abnormalities or skeletal dysplasia. His score in the Noonan syndrome diagnostic criteria (36 of 157 points, 23%) was lower than the cutoff for diagnosis (50%). Whole-exome sequencing identified a heterozygous variant (c.922A>G: p.Asn308Asp) in and a maternally inherited hemizygous variant (c.1439C>T: p.Pro480Leu) in . The variant was a known causative mutation for Noonan syndrome. is a causative gene for neurodevelopmental and skeletal abnormalities and has also been implicated in 46,XY DSD. The p.Pro480Leu variant of was assessed as deleterious by analyses. These results provide evidence that whole-exome sequencing is a powerful tool for diagnosing patients with atypical disease manifestations. Furthermore, our data suggest a possible role of digenic mutations as phenotypic modifiers of Noonan syndrome.