Selenium, a trace element that is fundamental to human health, is incorporated into some proteins as selenocysteine (Sec), generating a family of selenoproteins. Sec incorporation is mediated by a multiprotein complex that includes Sec insertion sequence-binding protein 2 (SECISBP2; also known as SBP2). Here, we describe subjects with compound heterozygous defects in the SECISBP2 gene. These individuals have reduced synthesis of most of the 25 known human selenoproteins, resulting in a complex phenotype. Azoospermia, with failure of the latter stages of spermatogenesis, was associated with a lack of testis-enriched selenoproteins. An axial muscular dystrophy was also present, with features similar to myopathies caused by mutations in selenoprotein N (SEPN1). Cutaneous deficiencies of antioxidant selenoenzymes, increased cellular ROS, and susceptibility to ultraviolet radiation-induced oxidative damage may mediate the observed photosensitivity. Reduced levels of selenoproteins in peripheral blood cells were associated with impaired T lymphocyte proliferation, abnormal mononuclear cell cytokine secretion, and telomere shortening. Paradoxically, raised ROS in affected subjects was associated with enhanced systemic and cellular insulin sensitivity, similar to findings in mice lacking the antioxidant selenoenzyme glutathione peroxidase 1 (GPx1). Thus, mutation of SECISBP2 is associated with a multisystem disorder with defective biosynthesis of many selenoproteins, highlighting their role in diverse biological processes.

Thyroid transcription factor 1 (NKX2-1/TITF1) mutations cause brain-lung-thyroid syndrome, characterized by congenital hypothyroidism (CH), infant respiratory distress syndrome (IRDS) and benign hereditary chorea (BHC). The objectives of the present study were (i) detection of NKX2-1 mutations in patients with CH associated with pneumopathy and/or BHC, (ii) functional analysis of new mutations in vitro and (iii) description of the phenotypic spectrum of brain-lung-thyroid syndrome. We identified three new heterozygous missense mutations (L176V, P202L, Q210P), a splice site mutation (376-2A-->G), and one deletion of NKX2-1 at 14q13. Functional analysis of the three missense mutations revealed loss of transactivation capacity on the human thyroglobulin enhancer/promoter. Interestingly, we showed that deficient transcriptional activity of NKX2-1-P202L was completely rescued by cotransfected PAX8-WT, whereas the synergistic effect was abolished by L176V and Q210P. The clinical spectrum of 6 own and 40 published patients with NKX2-1 mutations ranged from the complete triad of brain-lung-thyroid syndrome (50%), brain and thyroid disease (30%), to isolated BHC (13%). Thyroid morphology was normal (55%) and compensated hypothyroidism occurred in 61%. Lung disease occurred in 54% of patients (IRDS at term 76%; recurrent pulmonary infections 24%). On follow-up, 20% developed severe chronic interstitial lung disease, and 16% died. In conclusion, we describe five new NKX2.1 mutations with, for the first time, complete rescue by PAX8 of the deficient transactivating capacity in one case. Additionally, our review shows that the majority of affected patients display neurological and/or thyroidal problems and that, although less frequent, lung disease is responsible for a considerable mortality.

In pregnant women with past or current Graves' disease, ultrasonography of the fetal thyroid gland by an experienced ultrasonographer is an excellent diagnostic tool. This tool in conjunction with close teamwork among internists, endocrinologists, obstetricians, echographists, and pediatricians can ensure normal fetal thyroid function.

A longer initial duration of euthyroid state with ATD seems to be the only variable related to the risk of hyperthyroidism relapse in children that can be manipulated. Ethnic origin, age, and severity of the disease at diagnosis may guide long-term disease management decisions.

Patients with cystic fibrosis (CF) are at risk of developing low bone mineral density (BMD) and fragility fractures. This paper presents consensus statements that summarise current knowledge of the epidemiology and pathophysiology of CF-related skeletal deficits and provides guidance on its assessment, prevention and treatment. The statements were validated using a modified Delphi methodology.

Although a few familial forms of congenital hypothyroidism (CH) due to thyroid dysgenesis (TD) have been reported, this disorder is usually considered to be sporadic. Recently, we reported that 2% of CH patients with TD have a positive familial history. The aim of this study was to describe the clinical characteristics of these familial cases and to compare them with sporadic cases. We used the French national population-based registry of the first 19-yr screening program, which included 14,416,428 screened neonates with a 100% recovery rate. Familial history of CH with TD was investigated by means of a questionnaire sent to the pediatricians (n = 592) who provided ongoing clinical care for the 4049 CH patients detected during this period, including 2863 CH cases due to TD. Information was obtained from 73% of these pediatricians who were following up 2472 CH patients with TD (86%). In all, 67 patients with a positive family history of CH with TD were referred, belonging to 32 multiplex families (i.e. including at least 2 affected members). Families were identified with ectopic gland (n = 12), athyreosis (n = 7), or both (n = 13). Comparison of familial with isolated cases showed a similar etiological diagnosis distribution of CH (40% vs. 33% for athyreosis and 60% vs. 67% for ectopic thyroid gland, respectively), whereas a significantly lower predominance of females was found in familial than in isolated cases (1.4 vs. 2.7; P < 0.03). Extrathyroidal congenital malformations were found with a similarly higher incidence in familial and isolated CH populations compared with the general population (respectively, 9% and 8.2% vs. 2.5%). In conclusion, although familial cases represent a minority of cases of congenital hypothyroidism caused by thyroid dysgenesis, they were observed in a significantly higher proportion (>15-fold) than would be expected from chance alone. This familial clustering, including athyreosis and ectopic thyroid gland, strongly suggests that genetic factors could be involved in thyroid dysgenesis with a common underlying mechanism for both etiological groups. Moreover, the high proportion of extrathyroidal congenital malformations in a population affected by CH due to TD suggests that the potential genetic factors involved in thyroid gland organogenesis are also involved in the development of other organs.

Thyroid dysgenesis is the most common cause of congenital hypothyroidism (CH) and its genetic basis is largely unknown. Here, we describe the second homozygous missense mutation in TTF-2 (or FOXE1), a transcription factor that has been implicated in thyroid development. Two male siblings, born to consanguineous parents, presented with CH, athyreosis and cleft palate and were found to be homozygous for a mutation corresponding to a serine to asparagine substitution at codon 57 (S57N) in the forkhead DNA binding domain of TTF-2. Their heterozygous parents were unaffected and this mutation was not found in 31 unrelated cases of athyreosis or normal controls. Consistent with its location, the S57N TTF-2 mutant protein showed impaired DNA binding and partial loss of transcriptional function. Such incomplete loss of TTF-2 function may account for the absence of choanal atresia and bifid epiglottis in our patients, anomalies which were present together with CH and cleft palate in two other individuals with the only other, more deleterious, TTF-2 mutation (A65V) described previously. Our observations support the role of TTF-2 in both thyroid and palate development but suggest phenotypic heterogeneity of this syndromic form of CH.

NKX2-1 (NK2 homeobox 1) is a critical regulator of transcription for the surfactant protein (SP)-B and -C genes (SFTPB and SFTPC, respectively). We identified and functionally characterized two new de novo NKX2-1 mutations c.493C>T (p.R165W) and c.786_787del2 (p.L263fs) in infants with closely similar severe interstitial lung disease (ILD), hypotonia, and congenital hypothyroidism. Functional analyses using A549 and HeLa cells revealed that NKX2-1-p.L263fs induced neither SFTPB nor SFTPC promoter activation and had a dominant negative effect on wild-type (WT) NKX2-1. In contrast, NKX2-1-p.R165W activated SFTPC, to a significantly greater extent than did WT NKX2-1, while SFTPB activation was only significantly reduced in HeLa cells. In accordance with our in vitro data, we found decreased amounts of SP-B and SP-C by western blot in bronchoalveolar lavage fluid (patient with p.L263fs) and features of altered surfactant protein metabolism on lung histology (patient with NKX2-1-p.R165W). In conclusion, ILD in patients with NKX2-1 mutations was associated with altered surfactant protein metabolism, and both gain and loss of function of the mutated NKX2-1 genes on surfactant protein promoters were associated with ILD in "Brain-Lung-Thyroid syndrome".