MTSS2-related neurodevelopmental disorder: Further delineation of the phenotype.

MTSS2-related neurodevelopmental disorder (MTSS2-related NDD) (MIM 620086) is characterized by intellectual developmental disorder with ocular anomalies and distinctive facial features (IDDOF). The only existing report to date described five individuals who exhibited an identical de novo c.2011C>T (p.Arg671Trp) variant in the MTSS2 gene. Herein, we report a new case of MTSS2-related NND in a male dizygotic twin who presented with IDDOF and severe intellectual disability. This patient also displayed additional clinical features, including low functioning autism, hypothyroidism, duodenal obstruction secondary to Ladd's bands, inguinal hernias, cryptorchidism, transient subperiosteal new bone formation, and short stature with delayed bone age, which had not been previously reported in association with the MTSS2-related NDD. Exome sequencing identified the recurrent c.2011C>T (p.Arg671Trp) variant in the MTSS2 gene. The mother and the other twin tested negative for the pathogenic variant, while the father's participation in the study was unavailable. This case confirms that the MTSS2-related NDD is caused by the recurrent MTSS2 missense variant p.Arg671Trp. The novel findings identified in our patient expand the phenotypic spectrum associated with this new autosomal dominant entity, but further studies on its genetic and clinical manifestations are still needed.

Clinical insights from an unusual Turner syndrome manifestation: Congenital cutis verticis gyrata.

Cutis verticis gyrata (CVG) is classified as primary or secondary according to the absence or presence of underlying soft tissue abnormalities. We report an infant with Turner syndrome (TS) who in addition presented with CVG on the scalp. The skin biopsy revealed a hamartoma-like lesion. We reviewed the clinical and histopathological findings of the 13 reported cases of congenital CVG in patients with TS, including ours. In 11 of them, CVG was localized on the skin of the scalp, mainly on the parietal region, and in two, on the forehead. Clinically, CVG had a flesh-colored aspect, with absent or sparse hair, and was not progressive. CVG was classified as primary in four patients who had skin biopsy and it was attributed to the intrauterine lymphedema of TS. However, histopathology in two of these patients identified dermal hamartoma as a secondary cause of CVG, and in three others, including ours, there were hamartomatous changes. Although further studies are required, previous findings support the proposal that some CVG may instead be dermal hamartomas. This report alerts clinicians to recognize CVG as a low-frequency manifestation of TS, but also to consider the possible co-occurrence of TS in all female infants with CVG.