Heterozygous carriers of succinyl-CoA:3-oxoacid CoA transferase deficiency can develop severe ketoacidosis.

Succinyl-CoA:3-oxoacid CoA transferase (SCOT, gene symbol OXCT1) deficiency is an autosomal recessive disorder in ketone body utilization that results in severe recurrent ketoacidotic episodes in infancy, including neonatal periods. More than 30 patients with this disorder have been reported and to our knowledge, their heterozygous parents and siblings have had no apparent ketoacidotic episodes. Over 5 years (2008-2012), we investigated several patients that presented with severe ketoacidosis and identified a heterozygous OXCT1 mutation in four of these cases (Case1 p.R281C, Case2 p.T435N, Case3 p.W213*, Case4 c.493delG). To confirm their heterozygous state, we performed a multiplex ligation-dependent probe amplification analysis on the OXCT1 gene which excluded the presence of large deletions or insertions in another allele. A sequencing analysis of subcloned full-length SCOT cDNA showed that wild-type cDNA clones were present at reasonable rates to mutant cDNA clones. Over the following 2 years (2013-2014), we analyzed OXCT1 mutations in six more patients presenting with severe ketoacidosis (blood pH ≦7.25 and total ketone body ≧10 mmol/L) with non-specific urinary organic acid profiles. Of these, a heterozygous OXCT1 mutation was found in two cases (Case5 p.G391D, Case6 p.R281C). Moreover, transient expression analysis revealed R281C and T435N mutants to be temperature-sensitive. This characteristic may be important because most patients developed ketoacidosis during infections. Our data indicate that heterozygous carriers of OXCT1 mutations can develop severe ketoacidotic episodes in conjunction with ketogenic stresses.

Angelman Syndrome Caused by Chromosomal Rearrangements: A Case Report of 46,XX,+der(13)t(13;15)(q14.1;q12)mat,-15 with an Atypical Phenotype and Review of the Literature.

Less than 1% of the cases with Angelman syndrome (AS) are caused by chromosomal rearrangements. This category of AS is not well defined and may manifest atypical phenotypes. Here, we report a girl with AS due to der(13)t(13;15)(q14.1;q12)mat. SNP array detected the precise deletion/duplication points and the parental origin of the 15q deletion. Multicolor FISH confirmed a balanced translocation t(13;15)(q14.1;q12) in her mother. Her facial appearance showed some features of dup(13)(pter→q14). Also, she lacked the most characteristic and unique behavioral symptoms of AS, i.e., frequent laughter, happy demeanor, and easy excitability. A review of the literature indicated that AS cases caused by chromosomal rearrangements can be classified into 2 major categories and 4 groups. The first category is paternal uniparental disomy 15, which is subdivided into isodisomy by de novo rob(15;15) and heterodisomy caused by paternal translocation. The second category is the deletion of the AS locus due to maternal reciprocal translocation, which is subdivided into 2 groups associated with partial monosomy by 3:1 segregation and partial trisomy by adjacent-2 segregation. Classification into these categories facilitates the understanding of the mechanisms of chromosomal rearrangements and helps in accurate diagnosis and genetic counseling of these rare forms of AS.

Intermittent X-linked thrombocytopenia with a novel WAS gene mutation.

X-linked thrombocytopenia (XLT) is caused by mutations in the WAS gene and characterized by thrombocytopenia with minimal or no immunodeficiency. Patients with XLT usually exhibit persistent thrombocytopenia, and intermittent thrombocytopenia has been described only in two families. Here, we report a patient with intermittent XLT carrying a novel missense mutation (Ala56Thr). He showed residual expression of Wiskott-Aldrich syndrome protein in the lymphocytes and platelets. There appeared to be an association between normal platelet numbers and a post infectious state. Our findings further support the importance of analysis of Wiskott-Aldrich syndrome protein in male patients who exhibit fluctuating courses of thrombocytopenia.

Guidelines for Newborn Screening of Congenital Hypothyroidism (2021 Revision).

Purpose of developing the guidelines: Newborn screening (NBS) for congenital hypothyroidism (CH) was started in 1979 in Japan, and early diagnosis and treatment improved the intelligence prognosis of CH patients. The incidence of CH was once about one in 5,000-8,000 births, but has been increased with diagnosis of subclinical CH. The disease requires continuous treatment and specialized medical facilities should conduct differential diagnosis and treatment in patients who are positive by NBS to avoid unnecessary treatment. The Guidelines for Mass Screening of Congenital Hypothyroidism (1998 version) were developed by the Mass Screening Committee of the Japanese Society for Pediatric Endocrinology in 1998. Subsequently, the guidelines were revised in 2014. Here, we have added minor revisions to the 2014 version to include the most recent findings. Target disease/conditions: Primary congenital hypothyroidism. Users of the Guidelines: Physician specialists in pediatric endocrinology, pediatric specialists, physicians referring pediatric practitioners, general physicians, laboratory technicians in charge of mass screening, and patients.

Clinical features of insulinoma in patients with multiple endocrine neoplasia type 1: analysis of the database of the MEN Consortium of Japan.

More than 50% of patients with multiple endocrine neoplasia type 1 (MEN1) develop gastroenteropancreatic neuroendocrine tumors (GEPNETs), and insulinoma is the second most common functioning GEPNET. Compared to other functioning and nonfunctioning GEPNETs in MEN1, insulinoma is considered to develop at a younger age. To clarify the clinical features of insulinoma developed in Japanese patients with MEN1, a recently constructed database of Japanese MEN1 patients was analyzed. Among 560 registered cases, insulinoma was seen in 69 patients and information on age at diagnosis was available for 54 patients. Tumors predominantly occurred in the body and tail of the pancreas. The mean age at diagnosis of insulinoma (34.8 ± 16.7 yrs) was significantly younger than that of gastrinoma (50.6 ± 14.3 yrs) and nonfunctioning tumor (44.7 ± 13.3 yrs) in patients with MEN1. Patients diagnosed as having insulinoma during middle-age (30 - 49 yrs) tended to have a long period from appearance of hypoglycemic symptoms to diagnosis of the tumor. Of note, 13 patients (24%) were diagnosed as having insulinoma before 20 yrs of age. Such young onset was not seen in other GEPNETs. Since the development of GEPNETs during adolescence is quite rare, insulinoma diagnosed before 20 yrs strongly suggests the presence of MEN1 and warrants further investigation, including MEN1 genetic testing. Also, clinicians should be aware that insulinoma can often be missed in middle-aged patients.

Three pediatric cases of symptomatic hyponatremia in Prader-Willi syndrome.

OBJECTIVES: A recent large retrospective cohort study of cases of hyponatremia in Prader-Willi syndrome (PWS), conducted at nine reference centers, showed that severe hyponatremia was rare in PWS (0.5%); furthermore, all cases involved adults. Here, we describe three pediatric cases of severe hyponatremia in PWS, with neurological symptoms. CASE PRESENTATION: The cases involved two girls and one boy, and only one patient showed uniparental disomy. All patients had hyponatremia during infancy and presented with clinical symptoms, such as convulsions. All three patients improved with intravenous fluids and fluid restriction, with no sequelae. CONCLUSIONS: We report three pediatric cases of symptomatic hyponatremia of unknown cause in PWS. In patients with PWS, especially those with neurological symptoms such as convulsions, it is necessary to take hyponatremia into consideration.

Tertiary hyperparathyroidism in patients with pseudohypoparathyroidism type 1a.

Pseudohypoparathyroidism type 1a (PHP1a) is a genetic disorder caused by heterozygous loss-of-function mutations on the maternal allele of the GNAS gene. Patients with PHP1a predominantly exhibit parathyroid hormone (PTH) resistance and physical features of Albright's hereditary osteodystrophy. We report two unrelated cases with PHP1a who developed tertiary hyperparathyroidism (HPT). Molecular analyses of the GNAS gene identified a previously known heterozygous 4-bp deletion (c. 565_568delGACT) in exon 7 in case 1 and a novel heterozygous missense mutation (p.Lys233Glu) in exon 9 in case 2. Both patients developed tertiary HPT associated with hyperfunctioning parathyroid glands during long-term treatment of hypocalcemia. Case 1 had severe osteoporosis and underwent parathyroidectomy. Case 2 was asymptomatic with no evidence of bone diseases associated with tertiary HPT. PHP1a patients are at risk of developing tertiary HPT and should be treated with sufficient doses of calcium and vitamin D to achieve serum PTH levels within the mid - normal to double the upper limit of the normal range, regardless of serum calcium levels.

Two cases of 22q11.2 deletion syndrome with anorectal anomalies and growth retardation.

Clinical features associated with the deletion of 22q11.2 are highly variable. Most are diagnosed by cardinal congenital heart disease or hypoparathyroidism. In cases without major features, an early accurate diagnosis of 22q11.2 deletion syndrome is difficult. Congenital anorectal malformations (ARM), which can be detected soon after birth, have been rarely reported in 22q11.2 deletion syndrome. We report two cases of 22q11.2 deletion syndrome with ARM who showed growth retardation. ARM was detected in both patients without congenital heart disease or hypoparathyroidism at early infancy and they were followed by pediatric surgeons. Later, failure to thrive or short stature became evident, and they consulted with pediatric endocrinologists who subsequently confirmed the diagnosis of 22q11.2 deletion by fluorescent in situ hybridization analysis. The combination of ARM and growth retardation may lead to an early diagnosis of 22q11.2 deletion syndrome.

Exploring the unique function of imprinting control centers in the PWS/AS-responsible region: finding from array-based methylation analysis in cases with variously sized microdeletions.

BACKGROUND: Human 15q11-13 is responsible for Prader-Willi syndrome (PWS) and Angelman syndrome (AS) and includes several imprinted genes together with bipartite elements named AS-IC (imprinting center) and PWS-IC. These concertedly confer allele specificity on 15q11-13. Here, we report DNA methylation status of 15q11-13 and other autosomal imprinted differentially methylated regions (iDMRs) in cases with various deletions within the PWS/AS-responsible region. METHODS: We performed array-based methylation analysis and examined the methylation status of CpG sites in 15q11-13 and in 71 iDMRs in six cases with various microdeletions, eight cases with conventional deletions within 15q11-13, and healthy controls. RESULTS: We detected 89 CpGs in 15q11-13 showing significant methylation changes in our cases. Of them, 14 CpGs in the SNORD116s cluster presented slight hypomethylation in the PWS cases and hypermethylation in the AS cases. No iDMRs at regions other than 15q11-13 showed abnormal methylation. CONCLUSIONS: We identified CpG sites and regions in which methylation status is regulated by AS-IC and PWS-IC. This result indicated that each IC had unique functions and coordinately regulated the DNA methylation of respective alleles. In addition, only aberrant methylation at iDMRs in 15q11-13 leads to the development of the phenotypes in our cases.

An inherited disorder characterized by repeated episodes of bilateral ballism: a case report.

This case report describes two siblings with a dyskinetic form of cerebral palsy who had repeated episodes of fever-induced bilateral ballistic movements. The boy and his sister experienced the first episodes during early childhood. The movements developed over several hours and required rapid intervention. Electroencephalograms during the attacks showed no paroxysms, and brain magnetic resonance imaging scans revealed no lesions. The brother died of acute renal failure at age 5 due to rhabdomyolysis after his fifth episode of prolonged bilateral ballistic movements. This is the first report of an inherited disorder characterized by repeated episodes of violent movements.

A novel mutation in the monocarboxylate transporter 8 gene in a boy with putamen lesions and low free T4 levels in cerebrospinal fluid.

We describe brain lesions in a patient with a monocarboxylate transporter 8 mutation. Imaging showed a high T2 lesion in the left putamen at age 3 and a right putamen lesion at age 6. Cerebrospinal fluid free thyroxine concentrations were low, with normal 3,3',5-triiodothyronine concentrations.