[Hypercalcemia and inactive mutation of CYP24A1. Case-study and literature review]. / Hypercalcémie par mutation inactivatrice du CYP24A1. Étude d'un cas et revue de la littérature.

We present the case of a family whose members have high levels of serum calcium (hypercalcaemia) by loss of function of the enzyme vitamin D 24-hydroxylase due to bi-allelic mutations in the CYP24A1 gene: c.443 T>C (p.Leu148Pro) and c.1187 G>A (p.Arg396Gln). 24-VITD hydroxylase is a key player in regulating the circulating calcitriol, its tissue concentration and its biological effects. Transmission is recessive. The estimated prevalence of stones in the affected subjects is estimated between 10 and 15%. The loss of peripheral catabolism of vitamin D metabolites in patients with an inactivating mutation of CYP24A1 is responsible for persistent high levels of 1,25-dihydroxyvitamin D especially after sun exposure and a charge of native vitamin D. Although there are currently no recommendations (French review) on this subject, this disease should be suspected in association with recurrent calcium stones with nephrocalcinosis, and a calcitriol-dependent hypercalcaemia with adapted low parathyroid hormone levels. Resistance to corticosteroid therapy distinguishes it from other calcitriol-dependent hypercalcemia. A ratio of 25-hydroxyvitamin D/24.25 hydroxyvitamin D>50, is in favor of hypercalcemia with vitamin D deficiency 24-hydroxylase. Genetic analysis of CYP24A1 should be performed at the second step. The current therapeutic management includes the restriction native vitamin D supplementation and the limitation of sun exposure. Biological monitoring will be based on serum calcium control and modulation of parathyroid hormone concentrations.

Monocentric study of 112 consecutive patients with childhood onset GH deficiency around and after transition.

OBJECTIVES: Our aim was to analyze a large cohort of childhood onset GH deficiency (CO-GHD) adults from a unique adult center, in order to analyze their clinical management and to study the metabolic and bone status in relation to GHD and to the other pituitary deficits, and to evaluate these parameters during the long-term follow-up. DESIGN AND METHODS: Observational retrospective cohort study on 112 consecutive CO-GHD adults transferred to our unit from 1st January 1994 to 1st March 2012. Evaluation of GHD in pediatrics and after transition was conducted following consensus guidelines. Data recorded from pediatric and adult files were GH doses, pituitary magnetic resonance imaging and function, and metabolic and bone status. RESULTS: Most patients presented with severe CO-GHD (64%) associated with other pituitary deficits (66%). CO-GHD was acquired in 56%, congenital in 33%, and idiopathic in 11% cases. Most patients (83%) stopped GH before transfer, at 16.3 years (median), despite persistence of GHD. Median age at transfer was 19.4 years. After transfer, GHD persisted in 101 patients and four of the 11 resolutive GHD were non idiopathic. IGF1 level was <-2 SDS in 70% of treated patients at transfer and in 34% of them after 3 years of treatment. Follow-up showed improvement in lipid profile and bone mineral density in severely persistent GHD patients under GH therapy. In multivariate analysis, the associated pituitary deficits seemed stronger determinant factors of metabolic and bone status than GHD. CONCLUSIONS: This study raises concern about discontinuation of GH replacement therapy in pediatrics in severely persistent GHD patients and about the often insufficient dose of GH in the treatment of adult patients.