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Alexander disease (AxD) is a neurodegenerative disease in astrocytes caused by a mutation in the gene encoding glial fibrillary acidic protein, GFAP. We herein present the case of a 12-year-old girl who showed intermittent exotropia at 3 years of age and central precocious puberty at 7 years of age. The periventricular and medulla oblongata showed high signal intensity on T2-weighted magnetic resonance imaging. The patient was diagnosed with AxD after direct sequencing revealing a de novo recurrent mutation, c.1246C>T (p.R416W) in GFAP. The transient expression of GFAPR416W in cells resulted in the significant formation of aggregates, which recapitulated the hallmark of AxD. We firstly utilized In Cell analyzer to prove the tendency of aggregate formation by mutants of GFAP.

Introduction Kallmann syndrome (KS) is a genetically heterogeneous condition characterized by hypogonadotropic hypogonadism (HH) and olfactory dysfunction. Although SOX10, a causative gene for Waardenburg syndrome (WS) and peripheral demyelinating neuropathy, central demyelination, WS, and Hirschsprung disease (PCWH) has previously been implicated in KS, the clinical significance of SOX10 variants as the cause of KS remains uncertain. Patients and Methods A total of 117 patients with KS underwent mutation screening of SOX10 and 14 other causative genes for KS/HH. Rare SOX10 variants were subjected to in silico and in vitro analyses. We also examined clinical data of the patients and their parents with SOX10 variants. Results Sequence analysis identified 2 heterozygous variants of SOX10 (c.1225G > T, p.Gly409* and c.475C > T, p.Arg159Trp) in patients 1–3, as well as in the parents of patients 1 and 3. The variants were assessed as pathogenic/likely pathogenic, according to the American College of Medical Genomics guidelines. Both variants lacked in vitro transactivating activity for the MITF promoter and exerted no dominant-negative effects. Patients 1–3 carried no pathogenic variants in other genes examined. The patients presented with typical KS, while such features were absent in the parents of patients 1 and 3. None of the 5 variant-positive individuals exhibited hypopigmentation, while 1 and 2 individuals exhibited complete and partial hearing loss, respectively. Conclusion These results provide evidence that SOX10 haploinsufficiency accounts for a small percentage of KS cases. SOX10 haploinsufficiency is likely to be associated with a broad phenotypic spectrum, which includes KS without other clinical features of WS/PCWH.

Background Cystinosis is a rare autosomal recessive lysosomal disorder characterized by the accumulation of cystine in lysosomes. Cystinosis is much rarer in Asian than Caucasian populations. There are only 14 patients have with cystinosis alive in Japan. Most cystinosis is the nephropathic infantile form, as indicated by its apparent and severe clinical manifestations, including renal and ocular symptoms. Patients with the nephropathic juvenile form account for 5% of those with cystinosis. Their diagnosis is frequently delayed and difficult because of slower progression to end-stage renal disease and fewer cystine crystals in the cornea. Molecular analysis and a cysteine-binding protein assay should be performed when patients with proximal tubulopathy of an unknown origin are encountered. Case presentation A 12-year-old boy had been suffering from Fanconi syndrome since he was 3 years old. He was only recently diagnosed despite repeated ophthalmological examinations. Corneal cystine crystals were found when he was 12 years old, and he was diagnosed with cystinosis by high free cystine content in granulocytes (6.36 nmol half-cystine/mg protein, normal: C and c.329 + 2 T > C. Both were splicing site variants causing exon 6 skipping proven by transcript analysis, although the functional prediction site showed c.329G > C, p.(Gly110Ala) as a benign missense substitution. The patient’s estimated glomerular filtration rate was 66.8 mL/min/1.73 m2. He was immediately treated with cysteamine after diagnosis. Conclusions Even if no ophthalmological abnormalities are present, nephropathic juvenile cystinosis should be suspected in children with Fanconi syndrome. Transcript analysis was useful to detect pathogenic splicing variants in this patient.

Kenny–Caffey syndrome (KCS) is a rare dysmorphologic syndrome characterized by proportionate short stature, cortical thickening and medullary stenosis of tubular bones, delayed closure of anterior fontanelle, eye abnormalities, and hypoparathyroidism. The autosomal dominant form of KCS (KCS type 2 [KCS2]) is distinguished from the autosomal recessive form of KCS (KCS type 1 [KCS1]), which is caused by mutations of the tubulin-folding cofactor E (TBCE) gene, by the absence of mental retardation. In this study, we recruited four unrelated Japanese patients with typical sporadic KCS2, and performed exome sequencing in three patients and their parents to elucidate the molecular basis of KCS2. The possible candidate genes were explored by a de novo mutation detection method. A single gene, FAM111A (NM_001142519.1), was shared among three families. An identical missense mutation, R569H, was heterozygously detected in all three patients but not in the unaffected family members. This mutation was also found in an additional unrelated patient. These findings are in accordance with those of a recent independent report by a Swiss group that KCS2 is caused by a de novo mutation of FAM111A, and R569H is a hot spot mutation for KCS2. Although the function of FAM111A is not known, this study would provide evidence that FAM111A is a key molecule for normal bone development, height gain, and parathyroid hormone development and/or regulation. © 2014 American Society for Bone and Mineral Research.

Kenny-Caffey syndrome (KCS) is a rare dysmorphologic syndrome characterized by proportionate short stature, cortical thickening and medullary stenosis of tubular bones, delayed closure of anterior fontanelle, eye abnormalities, and hypoparathyroidism. The autosomal dominant form of KCS (KCS type 2 [KCS2]) is distinguished from the autosomal recessive form of KCS (KCS type 1 [KCS1]), which is caused by mutations of the tubulin-folding cofactor E (TBCE) gene, by the absence of mental retardation. In this study, we recruited four unrelated Japanese patients with typical sporadic KCS2, and performed exome sequencing in three patients and their parents to elucidate the molecular basis of KCS2. The possible candidate genes were explored by a de novo mutation detection method. A single gene, FAM111A (NM_001142519.1), was shared among three families. An identical missense mutation, R569H, was heterozygously detected in all three patients but not in the unaffected family members. This mutation was also found in an additional unrelated patient. These findings are in accordance with those of a recent independent report by a Swiss group that KCS2 is caused by a de novo mutation of FAM111A, and R569H is a hot spot mutation for KCS2. Although the function of FAM111A is not known, this study would provide evidence that FAM111A is a key molecule for normal bone development, height gain, and parathyroid hormone development and/or regulation.

Nonclassical 3β-hydroxysteroid dehydrogenase deficiency (N3βHSDD) or nonclassica 121-hydroxylase deficiency (N21OHD) are considered to be one of the causes of premature pubarche (PP) and hirsutism, but the diagnostic criteria for N3βHSDD are not well established. Among 44 Japanese children with PP, hirsutism, acne and/or accelerate growth, 13 and elevated 60min ACTH-stimulated 17-hydroxypregnenolone (Δ5-17P)/17-hydroxyprogesterone (17-OHP), more than 2 SD above the mean of 31 other patients. Four had evevated 60 min Δ5-17P/17-OHP, more than 5 SD above the mean of 31 other patients. According to the stringent criteria, none had N3βHSDD. None had N21OHD. Less well defined criteria for diagnosing N3βHSDD may lead to overdiagnosis of this disease. It is not known whether this elevated ratio is a physiological or a pathological response.

We describe a rare case of congenital hypothyroidism and an extremely high serum thyrotropin (TSH) level caused by a combination of resistance to thyroid hormone (RTH) and a lingual thyroid. As the RTH mutant, R316C, was new, the optimum dose of levothyroxine was unclear. To aid in assessment of the therapy, we characterized the mutant R316C thyroid hormone receptor (TR) and compared it with a common mutant, R316H, using in vitro studies.The patient was a newborn female having severe hypothyroidism with a free thyroxine level of 0.36 ng/dL and a serum TSH level of 177 microU/mL. A scintiscan showed ectopic lingual thyroid tissue without a normal thyroid gland. Supplementation with levothyroxine at a dose of350 microg/day did not normalize the serum TSH level; however, the patient showed normal growth and intelligence at 14 years of age. Consistent with the results of a computer analysis, the binding of R316C to triiodothyronine (T3) was significantly decreased to 38% that of the wild type. Electrophoretic mobility shift assay demonstrated that like R316H, R316C did not form a homodimer, but formed a heterodimer with RXR. However, a glutathione-S-transferase pull-down assay showed reduced binding of R316C with NCoR in the absence of T3 and impaired release in the presence of T3. In addition, transient transfection experiments demonstrated that unlike R316H, R316C had severe impairment of transcriptional activity on genes both positively and negatively regulated by thyroid hormone. It also had a clear dominant negative effect on genes negatively, but not positively, regulated by thyroid hormone, including the TSH-releasing hormone and TSHbeta genes.This is the first reported case of a R316C TR mutation. The characteristics of the R316C mutant differed from those of the R316H mutant. Our findings suggest that R316C causes reduced association with and impaired release of NCoR, resulting in RTH predominantly at the pituitary level, and that slightly elevated serum TSH level with high dose of levothyroxine might be optimum for normal growth.

Serum levels of IGF-I were radioimmunoassayed after acid ethanol extraction in 1075 normal subjects from infants through young adults, and the normal range for each age was established. The mean value for infants which was relatively low increased gradually with age, and rose sharply after that reaching the peak levels at mid adolescence, then it decreased slowly to the young adult levels. Significantly higher mean values were observed in females at the age of 9, 10, 11 and 12 years. Each of 23 cases with pituitary dwarfism exhibited a lower concentration than the lower limit of the bone age matched normal range. All of the 59 normal variant short children except three showed normal values, but the values were distributed over the lower side of the range.

The biological activity of GH in serum from 10 adult volunteers, 6 children with normal stature, and 26 children with growth retardation was assessed using the Nb2 rat lymphoma cell bioassay and the IM-9 human lymphocyte receptor modulation assay. The bioassay/RIA ratios for both bioassays varied widely but the range of ratios found in the normal stature adults and children was not different than that found in the group of children with growth retardation, which included 4 children with a presumptive diagnosis of bioinactive GH. We conclude that the use of these two bioassays is a valid approach to the assessment of the bioactivity of the circulating molecular forms of GH and that a large number of children with disorders of growth can be screened to identify patients with bioinactive GH.

A 17-year-old boy presented with growth retardation, marked hepatomegaly, and sexual infantilism. Elevated fasting serum insulin levels and a blunted hypoglycemic response to exogenous insulin (up to 0.35 unit/kg) demonstrated severe insulin resistance. Neither anti-insulin nor anti-insulin receptor antibodies were present. The molecular size of his circulating insulin and its binding to IM-9 lymphocytes was normal. Despite high circulating insulin values, both erythrocytes and cultured skin fibroblasts showed normal insulin binding capacity and affinity. Tissue responsiveness was examined by measuring the insulin-induced increase in 2-deoxyglucose uptake into fibroblasts. Although the basal glucose transport rate was slightly lower than that of controls, the insulin-induced increase was normal. However, the normal increase in thymidine incorporation in response to insulin was blunted, as were the thymidine incorporation responses to epidermal growth factor and fibroblast growth factor. These studies demonstrate the possible existence of a new form of post-insulin receptor defect as a cause of insulin resistance, but underscore the difficulty that exists in defining the exact nature of the defect in these disorders.

A naturally occurring variant of human (h)GH, designated 20K, is equipotent with hGH(22K) in stimulating growth in hypophysectomized rats. However, despite high growth-promoting activity in vivo, 20K is a poor inhibitor of 125I-hGH(22K) binding to GH receptors in radioreceptor assays. In order to resolve the differences between bioassay and radioreceptor assay data, we have examined the binding of 20K to rat and rabbit liver GH receptors. Our data indicate that the GH receptor in rat liver binds 20K with an affinity only slightly lower than that for hGH(22K), in accordance with bioassay data. In the rabbit, however, 20K is bound with high affinity by only a small subset of the GH receptors which bind hGH(22K) with high affinity. The GH receptors which bind 20K appear to belong to the same of subset of receptors which bind rat and rabbit GH with high affinity.

Congenital primary hypothyroidism due to thyrotropin (TSH) unresponsiveness is a very rare disorder and only a few cases have been documented previously. To elucidate whether structural abnormalities in the TSH receptor (TSHR) could be a primary underlying mechanism of this disorder, we analyzed nucleotide sequence of the entire coding region of the TSHR gene in three patients diagnosed with congenital primary hypothyroidism associated with TSH unresponsiveness. Diagnosis of TSH unresponsiveness was largely made based on the following criteria: (a) congenital primary hypothyroidism with autosomal recessive inheritance, (b) a nongoitrous thyroid gland in a normal position with low thyroidal radioactive iodine uptake, (c) normal in vitro TSH bioactivity or absent in vivo response to exogenous TSH, and (d) absence of thyroid autoantibodies. The TSHR cDNA was successfully obtained from RNA of peripheral mononuclear leukocytes with reverse transcription and polymerase chain reaction, and was sequenced directly. Comparison of these nucleotide sequences with the normal TSHR sequence revealed no difference in the predicted amino acid sequence with a heterozygous polymorphism in codon 601 in one patient, indicating absence of TSHR structural abnormalities in these patients. Our results indicate that congenital primary hypothyroidism associated with TSH unresponsiveness is unlikely to be due to mutations in the TSHR-structure gene.