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Disorders of sex development (DSD) are a group of rare conditions characterized by discrepancy between chromosomal sex, gonads and external genitalia. Congenital abnormalities of the kidney and urinary tract are often associated with DSD, mostly in multiple malformation syndromes. We describe the case of an 11-year-old Caucasian boy, with right kidney hypoplasia and hypospadias. Genome-wide copy number variation (CNV) analysis revealed a unique duplication of about 550 kb on chromosome Xq27, and a 46,XX karyotype, consistent with a sex reversal phenotype. This region includes multiple genes, and, among these, SOX3emerged as the main phenotypic driver. This is the fifth case reporting a genomic imbalance involving the SOX3gene in a 46,XX SRY-negative male, and the first with associated renal malformations. Our data provide plausible links between SOX3gene dosage and kidney malformations. It is noteworthy that the current and reported SOX3gene duplications are below the detection threshold of standard karyotypes and were found only by analyzing CNVs using DNA microarrays. Therefore, all 46,XX SRY-negative males should be screened for SOX3gene duplications with DNA microarrays.

Metatropic dysplasia (MD) is a rare skeletal dysplasia associated with heterozygous mutations in the TRPV4gene. We describe a 28-month-old boy with knock-knees referred for metabolic investigation suspected of carrying vitamin D-resistant rickets. He has received regular vitamin D prophylaxis at the usual dose. Laboratory investigations revealed normal values for calcium, phosphorus and alkaline phosphatase. He was short (-3.5 SDS), his mental development was normal, and he started to walk at the age of 22 months. The diagnostic clue for the diagnosis of metatropic dysplasia was the presence of the hump back in the upper lumbar and lower thoracic vertebrae, in addition to a long and narrow chest. An X-ray survey of the skeleton revealed platyspondyly, dysplastic metaphyses with dumbbell appearance of the long bones, kyphoscoliosis, and narrow and elongated thorax with short ribs. This is the first patient with MD in the Republic of Macedonia. Knock-knees were the cause of his referral, as a peculiarity of his phenotype. The very presence of the hump back, and the dumbbell appearance of the long bones distinguished the MD from other bone dysplasias with similar characteristics. We believe that the presence of those two features can shorten the path to accurate diagnosis in the crowded field of overlapping skeletal dysplasias. The diagnosis of MD in this patient was further confirmed by the discovery of the mutation c.2396C>T; p.Pro799Leu (P799L) of the TRPV4gene.