In 11 patients with a recessive congenital disorder, which we refer to as "the hypotonia-cystinuria syndrome," microdeletion of part of the SLC3A1 and PREPL genes on chromosome 2p21 was found. Patients present with generalized hypotonia at birth, nephrolithiasis, growth hormone deficiency, minor facial dysmorphism, and failure to thrive, followed by hyperphagia and rapid weight gain in late childhood. Since loss-of-function mutations in SLC3A1 are known to cause isolated cystinuria type I, and since the expression of the flanking genes, C2orf34 and PPM1B, was normal, the extended phenotype can be attributed to the deletion of PREPL. PREPL is localized in the cytosol and shows homology with prolyl endopeptidase and oligopeptidase B. Substitution of the predicted catalytic residues (Ser470, Asp556, and His601) by alanines resulted in loss of reactivity with a serine hydrolase-specific probe. In sharp contrast to prolyl oligopeptidase and oligopeptidase B, which require both aminoterminal and carboxyterminal sequences for activity, PREPL activity appears to depend only on the carboxyterminal domain. Taken together, these results suggest that PREPL is a novel oligopeptidase, with unique structural and functional characteristics, involved in hypotonia-cystinuria syndrome.
Context: Gender assignment followed by surgery and hormonal therapy is a difficult decision in the management of 45,X/46,XY patients with abnormal external genitalia at birth considering the paucity of studies evaluating pubertal development and fertility outcome, most notably for patients raised as boys. Objective: The purpose of this study was to describe the pubertal course of 20 45,X/46,XY patients born with ambiguous genitalia and raised as boys. Methods: This is a multicenter retrospective study. Results: Mean age at study was 25.6G2.4 years. Eighty-five percent of the patients presented a 'classical' mixed gonadal dysgenetic phenotype at birth. Puberty was initially spontaneous in all but three boys, although in six other patients, testosterone therapy was subsequently necessary for completion of puberty. Sixty-seven percent of the remaining patients presented signs of declined testicular function at the end of puberty (increased levels of FSH and low levels of testosterone and/or inhibin B). Moreover, an abnormal structure of the Y chromosome, known to alter fertility, was found in 10 out of 16 (63%) patients. Two patients developed testicular cancer. Half of the patients have adult penile length of !80 mm. Mean adult height is 156.9G2 cm, regardless of GH treatment. Conclusions: In summary, 45,X/46,XY children born with ambiguous genitalia and raised as boys have an altered pubertal course and impaired fertility associated with adult short stature, which should, therefore, be taken into consideration for the management of these patients.
Activating mutations of Galphas are present in 30% of juvenile OGCTs. The gsp oncogene, which is known to be implicated in cell proliferation and tumoral invasiveness, can be considered as a new prognostic factor of these tumors.
According to phenotype and functional studies, 11 of the mutations described, except the isolated p.R369W and p.I230T, may be responsible for a severe phenotype underlying the necessity to manage children having them. The p.I230T is a nonclassical mutation, and for the p.R369W, we need more cases to precise its severity.
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