Familial interstitial deletion of the short arm of chromosome 4 (p15.33-p16.3) characterized by molecular cytogenetic analysis.

This 15-month boy was expressed at the cytogenetic laboratory because of psychomotor development delay. He was tall and had plagiocephaly, micrognathia, high nasal bridge, anteverted nostrils and pectus excavatum. A 46,XY,del(4)(p16.1p16.3) karyotype was found using high-resolution R-banding technique. FISH studies using the LSI Wolf-Hirschhorn dual color 4p16.3 and the TelVysion 4p probes showed no deletion. Using BACs, the distal breakpoint was located in 4p16.3, between RP11-165K4 and RP11-717M10 and the proximal breakpoint in 4p15.33, between RP11-74M11 and RP11-1J7; therefore, approximately 7.96 Mb of the short arm were deleted. The maternal karyotype showed the same deletion, but in a mosaic status. Two distinct phenotypes have been recognized on the basis of the chromosomal bands involved in 4p deletion: the Wolf-Hirschhorn syndrome (WHS) and a proximal 4p deletion syndrome (4p15.2-p15.32). Our observation confirms that the basic WHS phenotype maps distally to this region.

NNT mutations: a cause of primary adrenal insufficiency, oxidative stress and extra-adrenal defects.

OBJECTIVE: Nicotinamide nucleotide transhydrogenase (NNT), one of the several genes recently discovered in familial glucocorticoid deficiencies (FGD), is involved in reactive oxygen species detoxification, suggesting that extra-adrenal manifestations may occur, due to the sensitivity to oxidative stress of other organs rich in mitochondria. Here, we sought to identify NNT mutations in a large cohort of patients with primary congenital adrenal insufficiency without molecular etiology and evaluate the degree of adrenal insufficiency and onset of extra-adrenal damages. METHODS: Sanger or massive parallel sequencing of NNT and patient monitoring. RESULTS: Homozygous or compound heterozygous NNT mutations occurred frequently (26%, 13 unrelated families, 18 patients) in our cohort. Seven new mutations were identified: p.Met337Val, p.Ala863Glu, c.3G>A (p.Met1?), p.Arg129*, p.Arg379*, p.Val665Profs*29 and p.Ala704Serfs*19. The most frequent mutation, p.Arg129*, was found recurrently in patients from Algeria. Most patients were diagnosed belatedly (8-18 months) after presenting severe hypoglycemia; others experiencing stress conditions were diagnosed earlier. Five patients also had mineralocorticoid deficiency at onset. One patient had congenital hypothyroidism and two cryptorchidism. In follow-up, we noticed gonadotropic and genitalia impairments (precocious puberty, testicular inclusions, interstitial Leydig cell adenoma, azoospermia), hypothyroidism and hypertrophic cardiomyopathy. Intrafamilial phenotype heterogeneity was also observed. CONCLUSIONS: NNT should be sequenced, not only in FGD, but also in all primary adrenal insufficiencies for which the most frequent etiologies have been ruled out. As NNT is involved in oxidative stress, careful follow-up is needed to evaluate mineralocorticoid biosynthesis extent, and gonadal, heart and thyroid function.