Endocrine Abstracts

Glucocorticoid resistance syndrome, a rare genetic disease, is often associated with glucocorticoid receptor (GR) loss-of-function mutations. Six patients carrying heterozygous mutations of NR3C1 gene encoding GR, either missense R477S, Q501H, L672P or non-sense R469X, R491X, Y660X mutations were studied. Surprisingly, NR3C1 mutation carriers presented with low kalemia, low plasma renin and aldosterone levels associated or not with arterial hypertension, cons...

The Mineralocorticoid Receptor (MR), a hormone-activated transcription factor that mediates sodium-retaining action of aldosterone, is highly expressed in the distal nephron in which large variations in extracellular fluid tonicity are generated by the cortico-papillary gradient. However, mechanisms regulating MR expression remain sparse. We recently showed that extracellular tonicity modulates renal MR expression through posttranscriptional mechanisms (Viengchareun, Mol Endoc...

PHP1B -iPPSD3 per the new proposed classification- is a rare disorder characterized in most patients by proximal tubular resistance to PTH resulting in hypocalcemia, hyperphosphatemia and elevated PTH. Loss-of-methylation (LOM) at the Differentially Methylated Region (DMR) at GNAS exon A/B occurs in all PHP1B patients, but methylation changes at other DMRs within GNAS occur in some familial and most sporadic PHP1B cases. All patients with autosomal dominant PHP1B (AD-...

Missense loss-of-function mutations in TAC3 and TACR3, the genes encoding neurokinin B (NKB) and its receptor NK3R, respectively, were recently discovered in kindreds with non syndromic normosmic congenital hypogonadotropic hypogonadism (nCHH), thus identifying a fundamental role of this pathway in the human gonadotrope axis.We investigated the consequences on gonadotrope axis of TAC3 and TACR3 invalidations in adult patients ...

Glucocorticoid receptor (GR or NR3C1) is a ligand-dependent transcription factor that plays an essential role in differentiation, development, inflammatory responses and energy balance and is implicated in several human diseases. Eleven germinal GR mutations have been described so far, responsible for glucocorticoid resistance with variable clinical presentation.We report original heterozygous GR mutations in three independent patients, which have been i...

The Mineralocorticoid Receptor (MR, NR3C2) mediates sodium-retaining action of aldosterone. Recently, we have shown that the physiological sodium loss observed in newborns in their first days of life is due to a low renal MR expression. However, the underlying molecular mechanisms remain unknown to date. In the adult renal KC3AC1 cell line, we demonstrated that variations in extracellular tonicity, which exist in the nephron, modulate MR expression by posttranscriptio...

Primary generalized glucocorticoid resistance is characterized by glucocorticoid excess without any Cushing syndrome. Patients exhibit variable clinical presentation including arterial hypertension, hirsutism or adrenal hyperplasia. Although glucocorticoid resistance has been associated with glucocorticoid receptor (GR) mutations (encoded by NR3C1 gene), only 23 mutations have been reported so far. We have conducted a French National Research Program, referred to as M...

Context: KISS1R mutations have been implicated in patients with normosmic congenital hypogonadotropic hypogonadism (nCHH) (OMIM #146110).Objective: To describe in detail nCHH patients with biallelic KISS1R mutations belonging to two unrelated families, and to functionally characterize a novel KISS1R mutation.Results: The p.Tyr313His original mutant was found in the homozygous state in three affected kindr...

Introduction: Paradoxical increase of GH following oral glucose load has been described in ~30% of patients with acromegaly and has been related to the ectopic expression of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) in somatotropinomas. Recently, we identified germline pathogenic variants of lysine demethylase 1A (KDM1A) in patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing’s syndrome. Patients...

Normosmic congenital hypogonadotropic hypogonadism (nCHH) is a rare reproductive disease leading to lack of puberty and infertility. Loss-of-function mutations of GNRH1 gene are a very rare cause of autosomal recessive nCHH. R31C GNRH1 is the only missense mutation that affects the conserved GnRH decapeptide sequence. This mutation was identified in a CpG islet in nine nCHH subjects from four unrelated families, giving evidence for a putative ‘hot spot&#...