Aberrant Splicing Is the Pathogenicity Mechanism of the p.Glu314Lys Variant in CYP11A1 Gene.

Context: The cholesterol side chain cleavage enzyme (CYP11A1) catalyzes the conversion of cholesterol to pregnenolone, the first rate-limiting step of steroidogenesis. CYP11A1 mutations are associated with primary adrenal insufficiency (PAI) as well as disorders of sex development (DSD) in 46,XY patients. Objective: To define the pathogenicity mechanism for the p.Glu314Lys variant, previously reported, and found in four additional patients with CYP11A1 deficiency. Subjects and Methods: DNA of four patients presenting with delayed PAI and/or 46,XY DSD were studied by Sanger or Massively Parallel sequencing. Three CYP11A1 mutations were characterized in vitro and in silico, and one by mRNA analysis on testicular tissue. Results: All patients were compound heterozygous for the previously described p.Glu314Lys variant. In silico studies predicted this mutation as benign with no effect on splicing but mRNA analysis found that it led to incomplete exon 5 skipping. This mechanism was confirmed by minigene experiment. The protein carrying this mutation without exon skipping should conserve almost normal activity, according to in vitro studies. Two other mutations found in trans, the p.Arg120Gln and p.Arg465Trp, had similar activity compared to negative control, consistent with the in silico studies. Conclusions: We provide biological proof that the p. Glu314Lys variant is pathogenic due to its impact on splicing and seems responsible for the moderate phenotype of the four patients reported herein. The present study highlights the importance of considering the potential effect of a missense variant on splicing when it is not predicted to be disease causing.

Impaired puberty, fertility, and final stature in 45,X/46,XY mixed gonadal dysgenetic patients raised as boys.

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 25.6±2.4 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 156.9±2 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.

IMAGe association and congenital adrenal hypoplasia: no disease-causing mutations found in the ACD gene.

The spontaneous mouse mutant adrenocortical dysplasia (acd) is characterized by defects in the adrenals, kidneys, and gonads of adult mutant mice and by caudal dysgenesis and vertebral segmentation defects in acd embryos. This association of defects mirrors those identified in patients with known or suspected abnormalities in adrenocortical development, including adrenal hypoplasia congenita and IMAGe association. The identification of the Acd gene in mice has prompted the study of its human homolog ACD, which has recently been shown to be a regulator of telomere length. Sequencing of ACD in 15 patients revealed no coding mutations, but three novel SNPs were identified.

Activating mutations of the stimulatory g protein in juvenile ovarian granulosa cell tumors: a new prognostic factor?

CONTEXT: Conflicting data have been reported regarding the presence of a constitutive activation of Galphas in ovarian granulosa cell tumors (OGCTs). Although the precise role of this mutation in the transformation of ovarian cells into malignant cells remains debatable, it has been demonstrated in other tissues that the rate of cell proliferation and invasiveness can be influenced by the gsp oncogene. OBJECTIVE: The objective of this study was to determine whether activating mutations of Galphas or Galphai are present in juvenile OGCTs and, if so, whether these mutations are significant prognostic factors. DESIGN AND SETTING: This was a multicentric nationwide study. PATIENTS AND METHODS: Thirty children with juvenile OGCT were included from the malignant germinal tumor protocol of the French Society for Childhood Cancer. Genetic studies of the tumoral DNA used nested PCR, laser microdissection, and direct sequencing. RESULTS: Galphas-activating mutations in hot spot position 201 were found in nine patients (30%). Laser microdissection confirmed that mutations R201C and R201H were exclusively localized in the tumoral granulosa cells and were absent in the ovarian stroma. Patients with a hyperactivated Galphas exhibited a significantly more advanced tumor (P < 0.05) because seven of them (77.7%) were staged as Ic or had had a recurrence. Galphai did not exhibit any mutation. CONCLUSIONS: 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.

Deletion of PREPL, a gene encoding a putative serine oligopeptidase, in patients with hypotonia-cystinuria syndrome.

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.

Postnatal changes of T, LH, and FSH in 46,XY infants with mutations in the AR gene.

Androgen insensitivity syndromes (AIS) result from the incapacity for T and dihydrotestosterone to virilize male embryos and is mainly attributable to molecular defects of the AR gene. In normal males, T and LH rise during the first few months of life, and this physiological surge is commonly used to evaluate the gonadotropic axis at this age. This neonatal surge has not been evaluated in detail in newborns with AIS. We sequentially measured plasma T, LH, and FSH during the first 3 months of life in 15 neonates with AIS and AR mutation. A GnRH and an human CG stimulation test were also performed. Patients were divided in 2 groups with complete (n = 10) or partial (n = 5) AIS (CAIS or PAIS), based on the clinical phenotype. In patients with PAIS, T levels were in the high-normal range at d 30 (18.4 +/- 6.9 nM) and d 60 (12.8 +/- 3.8 nM). In contrast, plasma T values were below the normal range in 9 of 10 patients with CAIS at d 30 (1 +/- 0.3 nM) and d 60 (1.4 +/- 0.7 nM, both P < 0.004 vs. PAIS). Plasma LH values were low in CAIS at d 30 (0.7 +/- 0.1U/liter) and increased normally in PAIS (8.7 +/- 2.5 U/liter, P = 0.004). We conclude that the postnatal T and LH surge occurs expectedly in neonates with PAIS but is absent in those with CAIS and that the postnatal T rise requires the receptivity of the hypothalamo-pituitary axis to T.