Michiyo Mizota

Mutation and Gene Copy Number Analyses of Six Pituitary Transcription Factor Genes in 71 Patients with Combined Pituitary Hormone Deficiency: Identification of a Single Patient with LHX4 Deletion

CONTEXT Mutations of multiple transcription factor genes involved in pituitary development have been identified in a minor portion of patients with combined pituitary hormone deficiency (CPHD). However, copy number aberrations involving such genes have been poorly investigated in patients with CPHD. OBJECTIVE We aimed to report the results of mutation and gene copy number analyses in patients with CPHD. SUBJECTS AND METHODS Seventy-one Japanese patients with CPHD were examined for mutations and gene copy number aberrations affecting POU1F1, PROP1, HESX1, LHX3, LHX4, and SOX3 by PCR-direct sequencing and multiplex ligation-dependent probe amplification. When a deletion was indicated, it was further studied by fluorescence in situ hybridization, oligoarray comparative genomic hybridization, and serial sequencing for long PCR products encompassing the deletion junction. RESULTS We identified a de novo heterozygous 522,009-bp deletion involving LHX4 in a patient with CPHD (GH, TSH, PRL, LH, and FSH deficiencies), anterior pituitary hypoplasia, ectopic posterior pituitary, and underdeveloped sella turcica. We also identified five novel heterozygous missense substitutions (p.V201I and p.H387P in LHX4, p.T63M and p.A322T in LHX3, and p.V53L in SOX3) that were assessed as rare variants by sequencing analyses for control subjects and available parents and by functional studies and in silico analyses. CONCLUSIONS The results imply the rarity of abnormalities affecting the six genes in patients with CPHD and the significance of the gene copy number analysis in such patients.

Proximal Promoter of the Cytochrome P450 Oxidoreductase Gene: Identification of Microdeletions Involving the Untranslated Exon 1 and Critical Function of the SP1 Binding Sites

CONTEXT POR (cytochrome P450 oxidoreductase) is a ubiquitously expressed gene encoding an electron donor to all microsomal P450 enzymes and several non-P450 enzymes. POR mutations cause an autosomal recessive disorder characterized by skeletal dysplasia, adrenal dysfunction, and disorders of sex development. Although recent studies have indicated the presence of a CpG-rich region characteristic of housekeeping genes around the untranslated exon 1 (exon 1U) and a tropic effect of thyroid hormone on POR expression via thyroid hormone receptor-β, detailed regulatory mechanisms for the POR expression remain to be clarified. OBJECTIVE Our objective was to report a pivotal element of the proximal promoter of POR. RESULTS We first studied three patients (cases 1-3) with POR deficiency due to compound heterozygosity with an p.R457H mutation and transcription failure of an apparently normal allele, by oligoarray comparative genomic hybridization and serial direct sequencing of the deletion fusion points. Consequently, a 2,487-bp microdeletion involving exon 1U was identified in case 1 and an identical 49,604-bp deletion involving exon 1U and exon 1 was found in cases 2 and 3. We next analyzed the 2,487-bp region commonly deleted in cases 1-3 by in silico analysis, DNA binding analysis, luciferase assays, and methylation analysis. The results showed a critical function of the evolutionally conserved SP1 binding sites just upstream of exon 1U, especially the binding site at the position -26/-17, in the transcription of POR. CONCLUSIONS The results suggest that the SP1 binding sites constitute an essential element of the POR proximal promoter.

Serratia marcescens lung abscess in a child with autoimmune neutropenia

Though Serratia marcescens is widely known to be the cause of serious infections in immuno‐compromised hosts, a lung abscess caused by S. marcescens is very rare. A 5 year old boy who had previously been diagnosed with autoimmune neutropenia was admitted because of fever and cough. In spite of treatment with some antibiotics, he developed a lung abscess. Aspiration of the pleural fluid revealed that S. marcescens was the pathogen of the disease. In the present case, there were feasible risk factors for the development of Serratia lung abscess namely neutropenia, chronic gingivitis at the time, and treatment with cyclosporin A. There are no reported cases of autoimmune neutropenia which developed into a S. marcescens lung abscess in the literature as far as we can determine.

Bilateral Asynchronous Adrenocortical Adenoma in a Girl with Beckwith-Wiedemann Syndrome

We report a case of asynchronous occurrence of bilateral adrenocortical adenoma in a 13-yr-old girl with Beckwith-Wiedemann syndrome. A right virilizing adrenal adenoma was surgically removed at age 6, following clinical manifestation of virilization such as acne, voice change, clitoris hypertrophy and overgrowth. Histopathological examination of the resected specimen revealed an adrenocortical adenoma predominantly composed of eosinophilic tumor cells expressing all the steroidogenic enzymes. High serum levels of DHEA-S (6,380 ng/ml) and testosterone (547 ng/dl) were noted prior to the operation. Postoperative course was unremarkable. Menstruation started at age 11, with a regular interval. At the age of 13 yr old, a high serum level of DHEA-S (8,250 ng/ml) was detected. In contrast to the episode of virilization at age 6, however, the serum testosterone level was not so high (122 ng/dl), and no clinical symptoms of virilization were apparent. Abdominal ultrasonography demonstrated the presence of a left adrenocortical adenoma. Pathological examination of the resected specimen revealed a circumscribed and well encapsulated tumor with essentially the same histological features as the tumor previously removed, except that the tumor cells showed a more prominent morphological similarity to the fetal adrenal cortex and did not express 3β HSD. The absence of virilization at the second episode was due to the relatively low serum level of testosterone compared with that of DHEA-S.

A 6-year-old boy with secondary long QT syndrome

Secondary long QT syndrome (LQTS) is caused by several drugs, cardiac conditions, and noncardiac conditions. One of the main metabolic causes is hypokalemia. We experienced treating a boy with secondary LQTS due to primary aldosteronism. The boy had been followed annually since he was 6 years old because his resting electrocardiogram (ECG) showed a prolonged QT interval. When he was 9 years old, he developed general fatigue and myalgia. The QT interval in his resting ECG became longer and serum data indicated rhabdomyolysis. The aldosterone level was high and renin activity was low. He was diagnosed with primary aldosteronism. When we, pediatricians, see children with LQTS, we are apt to think that their condition is congenital in nature. However, secondary or acquired LQTS should be always taken into consideration and be excluded not only in adults but also in the pediatric population.

Kawasaki syndrome and 21-hydroxylase deficiency

© 2008 Japan Pediatric Society Congenital adrenal hyperplasia is a family of autosomal recessive disorders of cortisol biosynthesis. 1 More than 90% of congenital adrenal hyperplasia cases are caused by 21-hydroxylase defi ciency (21-OHD). 1 Patients with 21-OHD are treated with glucocorticoids and patients with salt-wasting disease require mineralocorticoid replacement with fl udrocortisone. Kawasaki syndrome (KS) is a systemic vasculitis of unknown etiology that occurs commonly in children under 5 years of age 2 and results in coronary artery abnormalities (CAA) in 15 – 25% of those affected. 2,3 KS is not a rare disease in Japanese children; it occurs in more than 7000 children a year. 4 In contrast, the prevalence of congenital adrenal hyperplasia is 1/15 000 – 20 000. 1 Because of the rarity of this disease, there are no reports of 21-OHD patients developing KS. We encountered a patient with KS who was followed with 21-OHD. The patient recovered without any coronary abnormalities on a treatment of steroid, aspirin, and i.v. -globulin. This case suggests the importance of adequate additional steroid therapy for congenital adrenal hyperplasia in severe infl ammation, especially KS.

Two cases of atrophic thyroiditis with unilateral low radioiodine uptake on the right lobe in thyroid scintigram

An 11-year-old boy was first referred to Kagoshima University Hospital, Kagoshima, Japan, because of his short stature. A decrease in his growth velocity started at the age of 4 years (Fig. 1a). The patient also had constipation. His height was 111.7 cm (–4.0 standard deviation [SD]), and his weight was 22.5 kg (–2.0 SD). Struma was not detected, and his urogenitalia was at the prepubertal stage. Laboratory data revealed severe hypothyroidism (free thyroxine 4 [FT4] 0.19 ng/dL, thyrotropin [TSH] 1034 μ IU/mL). A thyroid test was positive (1600 × ), as was a microzome test (1600 × ). TSH-binding inhibitor immunoglobulins were negative. The patient’s insulin-like growth factor 1 [IGF-1] levels were 65.9 ng/mL. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were revealed to be prepubertal (0.4 mIU/mL and 4.0 mIU/mL). No abnormalities were noted in the peripheral blood. Mildly high levels of total cholesterol (T-cho; 269 mg/dL) were noted in the biochemistry. The patient’s bone age was 4 years by the Tanner–Whitehouse II (TW II) method, and he had mental retardation (IQ 63) by Suzuki Binet test. Reduced 123 I uptake of the right lobe and swelling of the left lobe were observed in thyroid scintigram (Fig. 2a). The results from the echography of the thyroid, right lobe, showed atrophic change and high intensity (Fig. 2b).

A Case with Hyperthyroidism Who Had Been Treated with Thyroid Hormone Because of Congenital Hypothyroidism

We encountered a case with hyperthyroidism at the age of 14 who had been diagnosed with congenital hypothyroidism (CH) and had received thyroid hormone replacement therapy. At the age of 16 d, the patient was referred to our hospital because of positive results at neonatal screening for CH. Serum level of TSH was 91.0 μU/ml and serum level of T4 was 6.9 μg/dl. The patient was diagnosed as having hypothyroidism, and hormone replacement therapy was started. Thereafter the dosage of thyroid hormone was adjusted and increased gradually as he grew to a maximum dose of 110 μg/day at the age of 11. Until the age of 13, the patient’s serum levels of TSH were within the normal range; then, at the age of 13 yr and 4 mo, his serum level of TSH dropped to a level below the detectable range. The dosage of administered thyroid hormone was tapered off and eventually eliminated at the age of 14. A thyroid scan and a radioactive iodine uptake test demonstrated a diffuse goiter with homogeneous uptake of radioactive iodine; the uptake rate was 60% at 24 h, and the serum level of TSH receptor antibody (TRAb) was 62.5% at that time. Administration of an antithyroid drug was started after confirmation that our patient had developed hyperthyroidism. There have been no case reports similar to our case.

Retrospective Analysis of Infants Designated as Positive on Mass-Screening for Congenital Hypothyroidism at Kagoshima University

Mass-screening for congenital hypothyroidism has identified cases of mild hypothyroidism, transient hypothyroidism, and transient hyperthyrotropinemia as well as typical hypothyroidism. In this paper, we examine the clinical data of the cases found positive in the screening test at our hospital. From 1989 to 1999 there were 72 patients with positive screening tests who started levothyroxine sodium (l-T4; Thyradin-S) as supplement therapy. At the age of 3 to 4 yr the patients were re-evaluated to determine whether treatment should be continued. Thyroid scintigraphies were done at the same time. We divided these cases into 4 groups. Those in group 1A started l-T4 in early infancy without a TRH test because of obvious clinical evidence of hypothyroidism, and treatment was continued after re-evaluation (n=37). Those in group 1B also started treatment in early infancy without a TRH test, but treatment was discontinued after re-evaluation (n=20). Patients in group 2A started l-T4 after evaluation by a TRH test and treatment was continued after re-evaluation (n=14), while those in group 2B started treatment after a TRH test, but after re-evaluation, treatment was discontinued (n=1). In group 2A, only a low dose of l-T4 was needed, and a slightly elevated TSH and slightly decreased free T4 (FT4) were observed after the drug washout period. However, these patients had an exaggerated response to the TRH test at re-evaluation. These findings indicate that this group, forming not a small part of whole screening-positive subjects, had mild hypothyroidism. Such patients require careful follow-up and repeated evaluation to determine whether treatment should be continued.