Loss-of-function mutations in the genes encoding prokineticin-2 or prokineticin receptor-2 cause autosomal recessive Kallmann syndrome.

CONTEXT: Physiological activation of the prokineticin pathway has a critical role in olfactory bulb morphogenesis and GnRH secretion in mice. OBJECTIVE: To investigate PROK2 and PROKR2 mutations in patients with hypogonadotropic hypogonadism (HH) associated or not with olfactory abnormalities. DESIGN: We studied 107 Brazilian patients with HH (63 with Kallmann syndrome and 44 with normosmic HH) and 100 control individuals. The coding regions of PROK2 and PROKR2 were amplified by PCR followed by direct automatic sequencing. RESULTS: In PROK2, two known frameshift mutations were identified. Two brothers with Kallmann syndrome harbored the homozygous p.G100fsX121 mutation, whereas one male with normosmic HH harbored the heterozygous p.I55fsX56 mutation. In PROKR2, four distinct mutations (p.R80C, p.Y140X, p.L173R, and p.R268C) were identified in five patients with Kallmann syndrome and in one patient with normosmic HH. These mutations were not found in the control group. The p.R80C, p.L173R, and p.R268C missense mutations were identified in the heterozygous state in the HH patients and in their asymptomatic first-degree relatives. In addition, no mutations of FGFR1, KAL1, GnRHR, KiSS-1, or GPR54 were identified in these patients. Notably, the new nonsense mutation (p.Y140X) was identified in the homozygous state in an anosmic boy with micropenis, bilateral cryptorchidism, and high-arched palate. His asymptomatic parents were heterozygous for this severe defect. CONCLUSION: We expanded the repertoire of PROK2 and PROKR2 mutations in patients with HH. In addition, we show that PROKR2 haploinsufficiency is not sufficient to cause Kallmann syndrome or normosmic HH, whereas homozygous loss-of-function mutations either in PROKR2 or PROK2 are sufficient to cause disease phenotype, in accordance with the Prokr2 and Prok2 knockout mouse models.

Classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency: a cross-sectional study of factors involved in bone mineral density.

Glucocorticoids are essential in the treatment of patients with congenital adrenal hyperplasia (CAH). The opposite actions of glucocorticoids and androgens in bone mass achievement justify a study of bone mineral density (BMD) in these patients. We evaluated BMD in patients with CAH due to classic 21-hydroxylase (CYP21A2) deficiency and investigated the involvement of clinical and laboratory factors in the BMD. This study assessed the clinical and laboratory factors involved in BMD of 45 patients at the Pediatric Unit of Endocrinology, UNICAMP, who had been diagnosed as having classical CAH due to CYP21A2 deficiency including molecular characterization. The sample consisted of 28 females and 17 males; 23 salt-wasting (SW) and 22 simple virilizing (SV) cases, with average of 9.9 years (ranges, 5.1-16.3 years) when bone densitometry was performed. The DEXA method was used for calculating the areal BMD Z score in L2-L4. The variables were analyzed with reference to the BMD for chronological age (BMD/CA), height age (BMD/HA), and bone age (BMD/BA). The mean Z score for BMD/CA was 0.08 +/- 1.21 (-2.55 to 2.64); it was 0.29 +/- 1.33 (-2.01 to 4.00) for BMD/HA, and -0.90 +/- 1.24 (-3.41 to 1.92) for BMD/BA. The BMD/CA was significantly lower in females and in patients on treatment for a long period and of more advanced chronological age. Weight and body mass index (BMI) Z scores showed a positive correlation with advanced BA. The higher the weight and BMI Z scores, the higher the BMD/HA. The BMD/BA values were significantly higher in the group in which BA was closer to CA. The BMD/BA value was significantly lower when compared to the value obtained with height and chronological ages. Sex, duration of treatment, weight, BMI, and bone age have an effect on areal BMD in patients with CAH due to CYP21A2 deficiency, which may be underestimated when evaluated in relation to CA and HA.