A novel case of 16q22.3 duplication syndrome in a child with overgrowth: case report and literature review.

BACKGROUND: Distal chromosome 16 duplication syndrome (also known as 16q partial trisomy) is a very rare genetic disorder recently described in few clinical reports. 16q trisomy is generally associated with a multisystemic phenotype including intrauterine growth restriction (IUGR), brain and cardiac defects, intellectual disability (ID) and an increased risk of both prenatal and postnatal lethality. Smaller copy number variants (CNV) within the 16q region create partial trisomies, which occur less frequently than full trisomy 16q. CASE PRESENTATION: We present the clinical case of a 12-years-old male with a 16q22.3q24.1 de novo heterozygous duplication whose phenotype was characterized by ID, facial dysmorphisms, stature and weight overgrowth. To date, only five other cases of this syndrome have been reported in scientific literature, and none of them comprised overgrowth. CONCLUSIONS: Our case report highlights the great heterogeneity in clinical manifestations and provides new evidence for better defining the phenotypic picture for smaller 16q distal CNVs, suggesting unusual features.

NR5A1 Gene Variants: Variable Phenotypes, New Variants, Different Outcomes.

NR5A1 (nuclear receptor subfamily 5 group A member 1) is a transcriptional regulator of adrenal and gonadal development and function. Heterozygous and homozygous NR5A1 mutations have been described in people with 46,XY disorders of sex development (DSD). The clinical, endocrine, and genetic features of four 46,XY subjects with NR5A1 genetic variants (2 sisters, 2 boys) from 3 unrelated families are reported. All subjects presented with hypergonadotropic hypogonadism and abnormal pubertal progression. Markers of Sertoli cell function were more affected than those of Leydig cell function. Genetic investigation demonstrated the presence of different heterozygous NR5A1 genetic variants. In the boys, pathogenetic NR5A1 gene variants were found that had been previously reported. The 2 sisters carried a new genetic variant in exon 4, and in silico analysis and ACMG classification indicated its pathogenicity. The data confirmed that NR5A1 gene mutations may present with variable genital phenotypes. Anyway, reproductive function was always impaired. Any clinical or endocrine data seem to be unable to differentiate these patients from other 46,XY DSD cases, suggesting that molecular analysis must be warranted. In subjects with NR5A1 mutations, different decisions in sex assignment may permit satisfying somatic and psychological outcome, but any option requires hormonal substitutive therapy from adolescence onward.