Background: Disordered thyroid hormone transport, due to mutations in the SLC16A2 gene encoding monocarboxylate transporter 8 (MCT8), is characterised by intellectual and motor disability resulting from cerebral hypothyroidism and chronic peripheral thyrotoxicosis. We sought to systematically assess the phenotypic characteristics and natural history of patients with MCT8 deficiency. Methods: We did an international, multicentre, cohort study, analysing retrospective data from Jan 1, 2003, to Dec 31, 2019, from patients with MCT8 deficiency followed up in 47 hospitals in 22 countries globally. The key inclusion criterion was genetically confirmed MCT8 deficiency. There were no exclusion criteria. Our primary objective was to analyse the overall survival of patients with MCT8 deficiency and document causes of death. We also compared survival between patients who did or did not attain full head control by age 1•5 years and between patients who were or were not underweight by age 1-3 years (defined as a bodyweight-for-age Z score <-2 SDs or <5th percentile according to WHO definition). Other objectives were to assess neurocognitive function and outcomes, and clinical parameters including anthropometric characteristics, biochemical markers, and neuroimaging findings. Findings: Between Oct 14, 2014, and Jan 17, 2020, we enrolled 151 patients with 73 different MCT8 (SLC16A2) mutations. Median age at diagnosis was 24•0 months (IQR 12•0-60•0, range 0•0-744•0). 32 (21%) of 151 patients died; the main causes of mortality in these patients were pulmonary infection (six [19%]) and sudden death (six [19%]). Median overall survival was 35•0 years (95% CI 8•3-61•7). Individuals who did not attain head control by age 1•5 years had an increased risk of death compared with patients who did attain head control (hazard ratio [HR] 3•46, 95% CI 1•76-8•34; log-rank test p=0•0041). Patients who were underweight during age 1-3 years had an increased risk for death compared with patients who were of normal bodyweight at this age (HR 4•71, 95% CI 1•26-17•58, p=0•021). The few motor and cognitive abilities of patients did not improve with age, as evidenced by the absence of significant correlations between biological age and scores on the Gross Motor Function Measure-88 and Bayley Scales of Infant Development III. Tri-iodothyronine concentrations were above the age-specific upper limit in 96 (95%) of 101 patients and free thyroxine concentrations were below the age-specific lower limit in 94 (89%) of 106 patients. 59 (71%) of 83 patients were underweight. 25 (53%) of 47 patients had elevated systolic blood pressure above the 90th percentile, 34 (76%) of 45 patients had premature atrial contractions, and 20 (31%) of 64 had resting tachycardia. The most consistent MRI finding was a global delay in myelination, which occurred in 13 (100%) of 13 patients. Interpretation: Our description of characteristics of MCT8 deficiency in a large patient cohort reveals poor survival with a high prevalence of treatable underlying risk factors, and provides ...

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare recessive disorder that results in several autoimmune diseases due to the mutations in the AIRE (autoimmune regulator) gene. APECED patients develop several autoimmune endocrine disorders and are characterized by the high titer autoantibodies to organ-specific antigens such as the steroidogenic P450 cytochromes. So far, 38 mutations have been identified in the AIRE gene. We report here the genetic and autoantibody analysis of 27 APECED patients of Eastern and Central European origins and one Egyptian patient. From 54 analyzed APECED chromosomes, eight mutations were detected, four of which (T16M, W78R, IVS1_IVS4, 30-53dup23bp) are novel. The most prevalent reason for APECED in these populations was the occurrence of R257X (36 chromosomes) that has been described earlier as a common and recurrent mutation in several other populations. The analysis of humoral immunity to steroidogenic P450 cytochromes by the immunoblotting of E. coli expressed antigens in the 18 APECED patients showed that 67%, 44%, and 61% of the Eastern and Central European APECED patients had autoantibodies to P450c17, P450c21, and P450scc, respectively.

Emerging evidence from murine studies suggests that mammalian sex determination is the outcome of an imbalance between mutually antagonistic male and female regulatory networks that canalize development down one pathway while actively repressing the other. However, in contrast to testis formation, the gene regulatory pathways governing mammalian ovary development have remained elusive. We performed exome or Sanger sequencing on 79 46,XX SRY-negative individuals with either unexplained virilization or with testicular/ovotesticular disorders/differences of sex development (TDSD/OTDSD). We identified heterozygous frameshift mutations in NR2F2, encoding COUP-TF2, in three children. One carried a c.103_109delGGCGCCC (p.Gly35Argfs∗75) mutation, while two others carried a c.97_103delCCGCCCG (p.Pro33Alafs∗77) mutation. In two of three children the mutation was de novo. All three children presented with congenital heart disease (CHD), one child with congenital diaphragmatic hernia (CDH), and two children with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). The three children had androgen production, virilization of external genitalia, and biochemical or histological evidence of testicular tissue. We demonstrate a highly significant association between the NR2F2 loss-of-function mutations and this syndromic form of DSD (p = 2.44 × 10−8). We show that COUP-TF2 is highly abundant in a FOXL2-negative stromal cell population of the fetal human ovary. In contrast to the mouse, these data establish COUP-TF2 as a human “pro-ovary” and “anti-testis” sex-determining factor in female gonads. Furthermore, the data presented here provide additional evidence of the emerging importance of nuclear receptors in establishing human ovarian identity and indicate that nuclear receptors may have divergent functions in mouse and human biology.

We recommend a routine molecular screening for hidden Y-chromosome sequences in Turner patients, who are negative for Y-chromosome by conventional cytogenetic analysis, in order to calculate the future risk of developing gonadoblastoma.

This is the first overview of patients diagnosed with APS I in Hungary. A novel c.1344delC mutation in AIRE was detected. Anti-IFN-omega antibodies seem to appear very early in life and are helpful to differentiate APS I from other multi-organ autoimmune diseases.