Biallelic loss-of-function variants of EZH1 cause a novel developmental disorder with central precocious puberty.

Pathogenic variants of polycomb repressive complex-2 (PRC2) subunits are associated with overgrowth syndromes and neurological diseases. EZH2 is a major component of PRC2 and mediates the methylation of H3K27 trimethylation (H3K27me3). Germline variants of EZH2 have been identified as a cause of Weaver syndrome (WS), an overgrowth/intellectual disability (OGID) syndrome characterized by overgrowth, macrocephaly, accelerated bone age, intellectual disability (ID), and characteristic facial features. Germline variants of SUZ12 and EED, other components of PRC2, have also been reported in the WS or Weaver-like syndrome. EZH1 is a homolog of EZH2 that interchangeably associates with SUZ12 and EED. Recently, pathogenic variants of EZH1 have been reported in individuals with dominant and recessive neurodevelopmental disorders. We herein present sisters with biallelic loss-of-function variants of EZH1. They showed developmental delay, ID, and central precocious puberty, but not the features of WS or other OGID syndromes.

Natural history and clinical features of hepatitis C virus infection during childhood: A nationwide, observational survey in Japan.

AIM: Few data on spontaneous clearance rates of cases of mother-to-child transmission of hepatitis C viral (HCV) infection are available in Japan. Furthermore, the treatment courses of interferon-based and direct-acting antiviral agent (DAA) therapies for children are also unclear. Our aim was thus to clarify the long-term natural progression of HCV infection and the treatment outcomes of children in Japan. METHODS: We conducted a combined multicenter, observational survey involving 65 pediatric institutions in Japan. Pediatric HCV infection cases with patients born between 1973 and 2021 were collected over the 11-year period from 2012 to 2022. A total of 563 patients were enrolled, with 190 excluded for having insufficient laboratory data or treatment information, resulting in 373 eligible cases. RESULTS: Of 328 cases of mother-to-child infection, 34 (10.4%) had spontaneous clearance, with a median time to spontaneous clearance of 3.1 years (range 0.9-7.2 years). Of the total 373 eligible cases, 190 received antiviral therapy (interferon-based therapy, 158; DAA therapy, 32). Sustained virologic response rates after first-line treatment were 75.3% (119/158) and 100% (32/32) for interferon-based therapy and DAA therapy, respectively, with the DAA group showing a shorter time from therapy initiation to viral negativity (2.7 vs. 1.0 months; p = 0.0031). CONCLUSIONS: Approximately 10% of Japanese children infected by mother-to-child transmission achieve spontaneous resolution of HCV infection. Our findings indicate that DAA therapy is safe and highly effective in Japanese children, achieving higher sustained virologic response rates and shorter time to clearance of the virus compared with interferon-based therapy.

Association between adeno-associated virus 2 and severe acute hepatitis of unknown etiology in Japanese children.

INTRODUCTION: Outbreaks of acute hepatitis of unknown etiology (AHUE) in children were reported in Western countries in 2022. Previous studies found that adeno-associated virus 2 (AAV2) and its helper viruses, such as human adenovirus (HAdV) and human herpesvirus-6 (HHV-6), are frequently detected in patients with AHUE. However, the existence of hepatitis associated with AAV2 prior to AHUE outbreaks in 2022 had not yet been investigated. We aimed to investigate the association between AAV2 and pediatric acute hepatitis in Japanese children, as well as the incidence of AAV2-related hepatitis prior to 2022. METHODS: Preserved blood samples obtained from 49 pediatric patients with acute hepatitis between 2017 and 2023 were retrospectively analyzed. Blood samples from 50 children with acute illnesses and 50 children with chronic conditions were used as controls. Viral DNA loads were quantitated using real-time PCR. RESULTS: AAV2 DNA was detected in 12 % (6/49) of acute hepatitis cases but in only one acute illness and none of the chronic-condition control cases. The concentration of AAV2 DNA in the six acute hepatitis cases was higher than that in the acute-illness control case. Co-infection with one or more helper viruses, including HAdV, HHV-6, cytomegalovirus, and Epstein-Barr virus, was observed in five AAV2-positive cases. CONCLUSIONS: Our results indicated the sporadic occurrence of pediatric severe hepatitis associated with AAV2 infection in Japan prior to the AHUE outbreaks in 2022. Our findings suggest that co-infection with AAV2 and helper viruses plays a role in developing severe hepatitis.

Serum leucine-rich alpha-2 glycoprotein and calprotectin in children with inflammatory bowel disease: A multicenter study in Japan.

BACKGROUND AND AIM: Serum leucine-rich alpha-2 glycoprotein (LRG) and calprotectin have been studied as disease activity markers in adults with inflammatory bowel disease (IBD). We evaluated them in pediatric IBD patients. METHODS: Subjects under 17 years old undergoing care at 11 Japanese pediatric centers were retrospectively assigned to 3 groups representing Crohn's disease (CD), ulcerative colitis (UC), and normal controls (NC) with irritable bowel syndrome or no illness. Serum LRG and calprotectin were measured using commercial enzyme-linked immunosorbent assay kits. RESULTS: We enrolled 173 subjects, including 74 with CD, 77 with UC, and 22 NC. Serum LRG concentrations in active CD (median, 200 µg/mL) were significantly greater than in remission (81 µg/mL; P < 0.001) or NC (69 µg/mL; P < 0.001). Serum calprotectin concentrations in active CD (2941 ng/mL) also were significantly greater than in remission (962 ng/mL; P < 0.05) or NC (872 ng/mL; P < 0.05). Serum LRG concentrations in active UC (134 µg/mL) were significantly greater than in remission (65 µg/mL; P < 0.01) but not significantly greater than in NC (69 µg/mL); serum calprotectin concentrations in active UC (1058 ng/mL) were not significantly different from those in remission (671 ng/mL) or NC (872 ng/mL). In receiver operating characteristic analyses of LRG, calprotectin, C-reactive protein, and erythrocyte sedimentation rate for ability to distinguish active IBD from remission, CD and UC showed areas under receiver operating characteristic curves for LRG (0.77 and 0.70, respectively), exceeding those for calprotectin, C-reactive protein, or erythrocyte sedimentation rate. CONCLUSIONS: In pediatric IBD, serum LRG may better reflect disease activity than serum calprotectin, particularly in CD.

Very young children with Prader-Willi syndrome are refractory to growth hormone-associated decreases in free thyroxine levels.

The earlier initiation of growth hormone (GH) treatment for patients with Prader-Willi syndrome (PWS) who are younger than 2 years has become more prevalent. Because free thyroxine (FT4) levels are low during this period, GH may induce further reductions; however, limited information is currently available on this issue. Therefore, we herein performed age-dependent and time-course analyses of thyroid hormone levels in GH-treated PWS children. This retrospective analysis included genetically diagnosed PWS patients (N = 37, median age of 26 months). An age-dependent analysis was performed by subdividing subjects based on age [a younger group aged between 1 and 24 months (N = 16) and an older group between 25 and 84 months (N = 21)] and was followed by a multiple regression analysis with adjustments for sex and the cumulative GH dose per bodyweight. A time-course analysis of subjects who had not received levothyroxine during the first 18 months of GH treatment (N = 28) was conducted. A one-month treatment with GH decreased FT4 levels in the older group, but not in the younger group, and this was associated with increases in thyroid-stimulating hormone levels. A positive correlation was noted between age and decreases in FT4 levels independent of the cumulative GH dose per bodyweight. The time-course analysis revealed no changes in FT4 levels in the younger group, while transient decreases were observed in the older group. In conclusion, GH treatment causes age-dependent changes in FT4 levels. This result will help clinicians establish a therapeutic strategy to decide the necessity of levothyroxine supplementation in GH-treated children with PWS.

Dosage of hydrocortisone during late infancy is positively associated with changes in body mass index during early childhood in patients with 21-hydroxylase deficiency.

Obesity is a major complication in children with 21-hydroxylase deficiency (21-OHD). There is evidence to show that higher body mass index (BMI) during infancy and early childhood is associated with an increased risk for the subsequent development of obesity in the general population; however, limited information is currently available on this issue in 21-OHD patients. Additionally, despite the frequent use of supraphysiological dosages of hydrocortisone in 21-OHD, the association between BMI and hydrocortisone dosage during these periods remains largely unclear; therefore, we retrospectively investigated BMI at approximately 1 and 3 years old and its association with hydrocortisone dosage in 56 children with 21-OHD. The median BMI-standard deviation score (SDS) was 0.28 (Interquartile range [IQR]: -0.53 to 1.09) and 0.39 (IQR: -0.44 to 1.14) at approximately 1 and 3 years old, respectively, and no association was observed between hydrocortisone dosage and BMI-SDS at either time-point; however, multivariate analysis revealed that hydrocortisone dosage at approximately 1 year old was positively associated with changes in BMI (ß = 0.57, p = 0.013) and BMI-SDS (ß = 0.59, p = 0.011) between approximately 1 and 3 years old after adjustment for age, sex, and changes in hydrocortisone dosage during the same period. The average dosage of hydrocortisone between approximately 6 months and 1 year old also showed similar results. These results indicate that a higher dosage of hydrocortisone during late infancy is associated with a higher BMI at approximately 3 years old, which may lead to the development of obesity later in life in children with 21-OHD.

Circulating insulin-like growth factor 1 levels are reduced in very young children with Prader-Willi syndrome independent of anthropometric parameters and nutritional status.

OBJECTIVE: Insulin growth factor-1 (IGF-1) is used to evaluate growth hormone (GH) sufficiency and is decreased in children with Prader-Willi syndrome (PWS). Although IGF-1 is negatively affected by body size and nutritional status, both of which are impaired in PWS children, these variables are typically not considered when assessing IGF-1 levels in these subjects. Here, we compared IGF-1 levels in PWS children to controls matched for age, sex, anthropometric parameters, and nutritional status. DESIGN/PATIENTS/MEASUREMENTS: The retrospective analysis included genetically diagnosed PWS subjects (n = 65, median age; 14.0 months) and controls (n = 111, 14.3 months) matched for age, sex, anthropometric parameters (height-standard deviation score [SDS], weight-SDS, body mass index-SDS), and serum albumin levels, a marker for nutritional status. IGF-1 SDS was compared between PWS subjects and controls after adjustment for confounding variables. The GH provocation test was performed in 29 PWS subjects, and IGF-1 SDS was compared between GH-sufficient (n = 20) and GH-deficient (n = 9) subjects. Spearman's rank correlation coefficient was performed to investigate the association between age and IGF-1 SDS. None had received GH or levothyroxine treatment. RESULTS: After adjustment for confounding variables, IGF-1 SDS was significantly lower in PWS subjects than controls (-1.56 vs. -1.01, p = .003), while it was not different between GH-sufficient and GH-deficient PWS subjects. Correlation analysis failed to show an association between age and IGF-1 SDS both in control and PWS groups. CONCLUSIONS: IGF-1 SDS is lower in very young children with PWS independent of anthropometric parameters and nutritional status, suggesting the presence of hypothalamic dysfunction of GH secretion.

Serum Zinc and Selenium in Children with Inflammatory Bowel Disease: A Multicenter Study in Japan.

BACKGROUND: Reports of zinc and selenium deficiencies accompanying inflammatory bowel disease (IBD) mostly have originated from Western countries and concerned adult patients. Whether Japanese children with IBD have similar deficiencies remained unclear. AIM: We aimed to elucidate differences in serum zinc and selenium concentrations in Japanese children between types of IBD. METHODS: Children under 17 years old undergoing care at 12 Japanese pediatric centers were retrospectively enrolled between November 2016 and February 2018 to 3 groups representing Crohn's disease (CD), ulcerative colitis (UC), and normal controls (NC) with irritable bowel syndrome or no illnesses. Serum zinc and selenium were measured by atomic absorption spectrophotometry. Zinc and selenium deficiencies were defined by serum concentrations < 70 µg/dL and < 9.5 µg/dL, respectively. RESULTS: Subjects included 98 patients with CD (median age, 13 years), 118 with UC (11 years), and 43 NC (11 years). Serum zinc and selenium were significantly lower in CD (median, 64 and 12.6 µg/dL respectively) than in UC (69 and 14.6; P < 0.05 and P < 0.001) or NC (77 and 15.7; P < 0.01 and P < 0.001). Zinc deficiency was significantly more prevalent in CD (60.2%) than in NC (37.2%; P < 0.05), but not than in UC (51.7%; P = 0.22). Selenium deficiency was significantly more prevalent in CD (15.3%) than in UC (5.9%; P < 0.05) or NC (0%; P < 0.01). CONCLUSIONS: In Japanese children under 17 years old, serum zinc and selenium were significantly lower in CD than in UC or NC. Zinc and selenium should be monitored, and supplemented when deficient, in children with IBD, especially CD.

Beta-human chorionic gonadotropin-producing neuroblastoma: an unrecognized cause of gonadotropin-independent precocious puberty.

The pathogenesis of gonadotropin-independent precocious puberty (PP) includes both congenital and acquired forms, the latter of which may be associated with neoplasms, such as sex-steroid hormone-producing tumors. Beta-human chorionic gonadotropin (ß-hCG)-producing tumors also cause gonadotropin-independent PP by stimulating the production of testosterone in Leydig cells. Germ cell tumors and hepatoblastoma both produce ß-hCG; however, there is limited evidence to show that gonadotropin-independent PP is caused by other ß-hCG-producing tumors. We herein report the first case of ß-hCG-producing neuroblastoma associated with the development of gonadotropin-independent PP. A 2-year-old boy presented with an increased penile length, enlargement of the testes, pigmentation of the external genitalia, and growth acceleration. Imaging, blood, and urinary examinations revealed the presence of neuroblastoma in the right adrenal region. Decreased levels of luteinizing hormone and follicle-stimulating hormone with an increased testosterone level were indicative of gonadotropin-independent PP. Since serum ß-hCG was elevated, ß-hCG-producing neuroblastoma was suspected. Histological findings of the resected tumor were compatible with neuroblastoma. An immunohistochemical analysis using serial sections revealed staining for ß-hCG in synaptophysin-positive cells. Furthermore, immunofluorescence showed the co-staining of ß-hCG with neuron-specific enolase. These results suggested that ß-hCG was produced by tumor cells. Surgical removal of the tumor promptly normalized serum ß-hCG and testosterone levels. In conclusion, we propose the addition of neuroblastoma to the list of differential diagnoses of gonadotropin-independent PP with ß-hCG positivity in serum that includes germ cell tumors and hepatoblastoma.

Clinical practice guidelines for the management of children with mother-to-child transmitted hepatitis C virus infection.

BACKGROUND: The first guidelines for care of pregnant women carrying the hepatitis C virus (HCV) and their infants were published in 2005 in Japan. Since then, evidence has gradually accumulated worldwide regarding the natural course and treatment of this condition and, especially in recent years, treatment for chronic hepatitis C in adult patients has made great progress. However, the clinical practice policy for children has not been standardized, and new clinical practice guidelines for children with mother-to-child (MTC) transmitted HCV infection have become necessary. METHODS: In the development of the current guideline, we requested cooperation from The Japanese Society for Pediatric Infectious Diseases, The Japan Society of Hepatology, and the Japan Society of Obstetrics and Gynecology. The committee members were recommended and approved by each society to participate in developing the guidelines. The guideline was also created in accordance with the Minds Guide for Practice Guideline Development. The statements were prepared by consensus-building using the Delphi method, based on the comprehensively searched academic papers and guidelines. These articles were retrieved through searching the PubMed, Cochrane Library, and the Igaku Chuo Zasshi databases. RESULTS: Eight clinical questions (CQs) with clinical statements were developed regarding etiology (CQs 1-3), diagnosis (CQs 4 and 5), and treatment (two CQs 6 and 7). In each statement, the consensus rate, evidence level, and recommendation level were determined. CONCLUSION: The guidelines will be helpful in the management of children with hepatitis C MTC transmission.

Central hypothyroidism improves with age in very young children with Prader-Willi syndrome.

OBJECTIVE: Abnormalities in the hypothalamic-pituitary-thyroid (HPT) axis have been implicated in Prader-Willi syndrome (PWS); however, limited information is currently available on age-dependent alterations in the HPT axis. We herein investigated age-dependent differences in thyroid hormone levels in PWS children. DESIGN/PATIENTS/MEASUREMENTS: Free T4 (FT4), free T3 (FT3) and thyroid-stimulating hormone (TSH) concentrations were retrospectively compared between genetically confirmed PWS children (N = 43, median age: 11.2 months) and controls (N = 85, median age: 14.5 months) matched for age, sex, body weight-SD score (SDS), height-SDS, body mass index-SDS and serum albumin level, a marker of the nutritional status. Subjects were subdivided into two groups based on their age: an infant group aged between 1 and 11 months (PWS: N = 22, controls: N = 30) and a toddler group aged between 12 and 47 months (PWS: N = 21, controls: N = 55). None of the subjects had ever been treated with growth hormone or levothyroxine. RESULTS: After adjustments for confounding variables, in the infant group, FT4 levels (pmol/L) were significantly lower in PWS (11.24 in PWS vs 14.32 in controls, P = .0002), whereas no significant differences were observed in FT3 or TSH levels. In the toddler group, no significant differences were noted in FT4 (12.23 in PWS vs 15.31 in controls, P = .10), FT3 or TSH levels. The FT3/FT4 ratio was significantly increased in PWS in both groups. FT4 levels were positively correlated with age in PWS. CONCLUSIONS: Infants with PWS had lower FT4 levels, but FT3 levels were normal, indicating that the levothyroxine replacement therapy may not need to be routinely performed.

Constitutional mismatch repair deficiency in childhood colorectal cancer harboring a de novo variant in the MSH6 gene: a case report.

BACKGROUND: Constitutional mismatch repair deficiency (CMMRD) is caused by biallelic pathogenic variants in one of the mismatch repair genes, and results in early onset colorectal cancer, leukemia, brain tumors and other childhood malignancies. Here we report a case of CMMRD with compound heterozygous variants in the MSH6 gene, including a de novo variant in multiple colorectal cancers. CASE PRESENTATION: An 11-year-old girl, who presented with multiple spots resembling café-au-lait macules since birth, developed abdominal pain, diarrhea and bloody stool over two months. Colonoscopy revealed multiple colonic polyps, including a large epithelial tumor, and pathological examination revealed tubular adenocarcinoma. Brain magnetic resonance imaging (MRI) showed an unidentified bright object (UBO), commonly seen in neurofibromatosis type 1 (NF1). Genetic testing revealed compound heterozygous variants, c. [2969T > A (p.Leu990*)] and [3064G > T (p.Glu1022*)] in the MSH6 gene; c.2969T > A (p.Leu990*) was identified as a de novo variant. CONCLUSIONS: We present the first report of a CMMRD patient with a de novo variant in MSH6, who developed colorectal cancer in childhood. CMMRD symptoms often resemble NF1, as observed here. Physicians should become familiar with CMMRD clinical phenotypes for the screening and early detection of cancer.

Diagnostic accuracy of serum proteinase 3 antineutrophil cytoplasmic antibodies in children with ulcerative colitis.

BACKGROUND AND AIM: Serologic markers such as myeloperoxidase (MPO) antineutrophil cytoplasmic antibodies (ANCA) (MPO-ANCA) have been used to screen patients for ulcerative colitis (UC). However, MPO-ANCA shows limited accuracy in Asians. Proteinase 3 ANCA (PR3-ANCA) has performed better at UC diagnosis in Japanese adults than MPO-ANCA. The present study aimed to evaluate usefulness of PR3-ANCA for diagnosis of UC in Japanese pediatric practice. METHODS: Patients under 17 years old undergoing assessment at 12 Japanese pediatric centers between November 2016 and February 2018 were prospectively enrolled and divided into groups with UC, Crohn's disease (CD), intestinal disease control (IC), and healthy control (HC). Serum PR3-ANCA and MPO-ANCA were analyzed using chemiluminescence enzyme immunoassay kits. RESULTS: Sera from 367 patients (148 with UC at a median age of 12 years; 120 with CD, 13 years; 56 with IC, 10.5 years; and 43 with HC, 10 years) were examined. Median PR3-ANCA values in UC (1.6 U/mL) were greater than in CD (0.2; P < 0.001), IC (0.15; P < 0.001), and HC (0.1; P < 0.001). In receiver operating characteristic curve analyses, the area under the curve for PR3-ANCA was 0.79, significantly greater than for MPO-ANCA (0.58; P < 0.001). Using a cut-off value of 0.8 U/mL determined from the receiver operating characteristic analyses, PR3-ANCA showed significantly greater sensitivity (64.9%) than MPO-ANCA (cut-off, 0.2 U/mL; sensitivity, 19.6%; P < 0.001) and good specificity (83.6%). CONCLUSIONS: In Japanese children and adolescents, PR3-ANCA performed better as a serologic marker for diagnosis of UC than MPO-ANCA. To our knowledge, this is the first report of such a comparison.

Renal function in short-statured children born small for gestational age and treated with growth hormone.

BACKGROUND: Children born small for gestational age (SGA), particularly when associated with an extremely low birthweight (ELBW), have a higher risk of renal dysfunction. Growth hormone (GH) treatment is used to treat short-statured children born SGA; however, its effects on renal function remain elusive, especially in those born SGA with ELBW. METHODS: Short-statured children born SGA (N = 42) were included. Subjects were subdivided into two groups based on their birthweight: the ELBW group (N = 15) with a birthweight of <1,000 g, and the non-ELBW group (N = 27) with birthweights ranging between 1,000 and 2,500 g. The creatinine-based estimated glomerular filtration rates (eGFR) before (pre-eGFR) and 5 years after GH treatment (post-eGFR) were compared. Correlations between eGFR, anthropometric, or birth parameters, and cumulative GH dose were evaluated using Spearman's rank correlation coefficient. RESULTS: The ELBW group had a lower pre- and post-eGFR than the non-ELBW group. Five-year GH treatment did not significantly reduce eGFR in either group. Post-eGFR was positively associated with gestational week and birthweight. However, the cumulative GH dose was not correlated with pre-eGFR, post-eGFR, or percentage change in eGFR (%ΔeGFR). The change in bodyweight standard deviation score during GH treatment was positively correlated with %ΔeGFR in the ELBW group. CONCLUSIONS: The current results indicated that GH treatment was unlikely a risk for the reduction in eGFR in short-statured children born SGA. However, eGFR should be carefully monitored, especially in those born SGA with ELBW because these subjects had lower eGFR than non-ELBW subjects.

Growth hormone treatment for extremely low birthweight children born small for gestational age.

BACKGROUND: The effectiveness of growth hormone (GH) treatment for height gain in short-stature children born small for gestational age (SGA) with extremely low birthweight (ELBW; birthweight <1,000 g) remains largely unknown. METHODS: In study 1, 35 prepubertal Japanese children born SGA with ELBW were categorized into three groups based on the presence or absence of catch-up growth by age 3 (CU(+) and CU(-), respectively) and GH treatment (GH(+) and GH(-), respectively). Height standard deviation (SD) scores (HT-SDS) in the CU-/GH+ group (n = 19) were compared with those in the age-matched CU+/GH- (n = 9) and CU-/GH- groups (n = 7). In study 2, 66 prepubertal Japanese SGA children treated with GH were divided into three groups by birthweight: <1,000 g (n = 19), 1,000-2,000 g (n = 20), and >2,000 g (n = 27). Changes in HT-SDS during the initial 3 years of GH treatment were compared among the three groups. RESULTS: In study 1, the mean HT-SDS in the CU-/GH+ group (-1.15 SD) was similar to that in the CU+/GH- group (-1.39 SD) but higher than that in the CU-/GH- group (-2.24 SD). In study 2, GH achieved a height gain of +1.62 SD in the ELBW group, which was similar to that in the other groups (1,000-2,000 g: +1.46 SD, >2,000 g: +1.53 SD). CONCLUSIONS: Growth hormone treatment in short-stature children born SGA with ELBW increased HT-SDS, which was similar to that in SGA children born with a birthweight ≥1,000 g. These results indicate that GH treatment may be an effective approach to promote adequate growth recovery for short-stature children born SGA with ELBW.

Comprehensive Targeted Sequencing Identifies Monogenic Disorders in Patients With Early-onset Refractory Diarrhea.

OBJECTIVES: Causes of early-onset refractory diarrhea include exudative diarrhea associated with very early-onset inflammatory bowel diseases, osmotic or secretory diarrhea, and protein-losing enteropathy. Monogenic disorders are included in these diseases, yet a comprehensive genetic analysis has not been fully established. METHODS: We established targeted gene panels covering all responsible genes for early-onset diarrhea. In total, 108 patients from 15 institutions were enrolled in this study. We collected clinical data from all patients. Seventy-three patients with exudative diarrhea, 4 with osmotic or secretory diarrhea and 8 with protein-losing enteropathy were subjected to genetic analysis. RESULTS: A total of 15 out of the 108 enrolled patients (13.9%) were identified as monogenic. We identified 1 patient with RELA, 2 with TNFAIP3, 1 with CTLA4, 1 with SLCO2A1, 4 with XIAP, 3 with IL10RA, 1 with HPS1, 1 with FOXP3, and 1 with CYBB gene mutations. We also identified 1 patient with NFKB2 and 1 with TERT mutations from the gene panel for primary immunodeficiency syndromes. The patient with refractory diarrhea caused by heterozygous truncated RelA protein expression is the first case identified worldwide, and functional analysis revealed that the mutation affected nuclear factor kappa B signaling. Genotypes were significantly associated with the clinical and pathological findings in each patient. CONCLUSIONS: We identified variable monogenic diseases in the patients and found that genes responsible for primary immunodeficiency diseases were frequently involved in molecular pathogenesis. Comprehensive genetic analysis was useful for accurate molecular diagnosis, understanding of underlying pathogenesis, and selecting the optimal treatment for patients with early-onset refractory diarrhea.An infographic for this article is available at: http://links.lww.com/MPG/B853.

Visceral adipose tissue resides within the reference range in children with Prader-Willi syndrome receiving nutritional intervention on a regular basis.

Nutritional intervention for maintaining an appropriate body composition is central to the management of Prader-Willi syndrome (PWS). Despite evidence that visceral adipose tissue (VAT) is associated with increased metabolic risks, the effects of nutritional intervention on fat distribution have not been evaluated for PWS children. We herein investigated fat distribution in 20 genetically diagnosed PWS children (9 males and 11 females); 17 of which received nutritional intervention with or without growth hormone (GH) treatment [GH-treated group (n = 8), GH-untreated group (n = 9)]. GH treatment continued for median of 4.9 years. GH treatment significantly increased height standard deviation score (SDS) whereas body weight SDS and body mass index SDS were not affected in GH-treated group. In GH-untreated group, height SDS significantly decreased during approximately 5 years of follow-up. Fat distribution was evaluated at the median age of 6.93 years in GH-treated group and 7.01 years in GH-untreated group. VAT was maintained within the reference range in both groups. Subcutaneous adipose tissue (SAT) was elevated in GH-untreated groups compared to reference values whereas it was not in GH-treated group. The remaining three subjects, who had never received nutritional intervention or GH treatment, showed increased VAT and SAT. In conclusion, nutritional intervention is beneficial in maintaining VAT within the reference range during childhood, although excessive nutritional intervention may cause unfavorable effect on linear growth.

Fat distribution in short-stature children born small for gestational age.

BACKGROUND: Children born small for gestational age (SGA) with catch-up growth are at high risk for developing obesity; however, the characteristics of body composition, especially fat distribution, before and after growth hormone (GH) treatment in SGA children without catch-up growth remains largely unknown. METHODS: Anthropometric characteristics, body composition by dual-energy X-ray absorption, and fat distribution by computed tomography at the umbilical level were examined in 27 prepubertal short-stature children born SGA before and 1 year after GH treatment. RESULTS: Before GH treatment, short-stature SGA children had lean phenotypes, and both visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were significantly lower than the age- and sex-matched Japanese reference values. Growth hormone treatment significantly increased height standard deviation scores (SDS), without affecting body mass index SDS. Percentage fat mass decreased with GH treatment; however, fat mass was not altered. Both VAT and SAT were significantly lower than the reference values after GH treatment. The ratio of VAT over SAT significantly increased by GH treatment. CONCLUSIONS: Both VAT and SAT were within or below the age- and sex-matched Japanese reference values in short-stature children born SGA before and after GH treatment, indicating that GH treatment may not have unfavorable effects on adiposity in short-stature children born SGA, although it may alter fat distribution.

Genotype-phenotype correlation analysis in Japanese patients with Noonan syndrome.

Noonan syndrome (NS) is a heterogeneous disorder with multiple congenital malformations. Recent advances in molecular and genetic approaches have identified a number of responsible genes for NS, most of which are components of the RAS/MAPK signaling pathway, and genotype-phenotype correlation analyses have been extensively performed; however, analysis of Japanese NS patients is limited. Here, we evaluated clinical characteristics in genetically diagnosed NS patients and their relationships to genotypes. A total of 48 clinically diagnosed NS were included, and responsible mutations were identified in 39 patients (81.3%) with PTPN11 mutations being the most prevalent followed by SOS1 mutations. Cardiac anomalies including pulmonary stenosis and hypertrophic cardiomyopathy were most prevalent (87.2%), and the prevalence of hypertrophic cardiomyopathy was greater in patients without PTPN11 mutations than in those with PTPN11 mutations. Short stature was the second-most prevalent (69.2%) characteristic, and present height SD score was significantly associated with height SD score at 1 year old. Patients with SOS1 mutations had greater present height SD score and better growth during infancy. These findings suggest the presence of a genotype-phenotype correlation in Japanese patients with NS, which enables us to use genetic information to predict the clinical course and may allow for genotype-based medical interventions.

Zinc monotherapy for young children with presymptomatic Wilson disease: A multicenter study in Japan.

BACKGROUND AND AIM: Few studies of zinc monotherapy for presymptomatic Wilson disease have focused on young children. We therefore evaluated long-term efficacy and safety of zinc monotherapy for such children and established benchmarks for maintenance therapy. METHODS: We retrospectively and prospectively examined children under 10 years old with presymptomatic Wilson disease who received zinc monotherapy from time of diagnosis at 12 participating pediatric centers in Japan. RESULTS: Twenty-four patients met entry criteria. Aspartate aminotransferase and alanine aminotransferase decreased significantly beginning 1 month after initiation of treatment and usually remained under 50 U/L from 1 to 8 years of treatment. Twenty four-hour urinary copper decreased significantly at 6 months and usually remained under 75 µg/day and between 1 and 3 µg/kg/day for the remainder of the study. All patients continued to take zinc, and none became symptomatic. In patients under 6 years old who received 50 mg/day of zinc as an initial dose, aspartate aminotransferase and alanine aminotransferase significantly decreased at 1 month after initiation of treatment, as did γ-glutamyltransferase and 24-h urinary copper at 6 months. CONCLUSIONS: To our knowledge, this is the first multicenter study of zinc monotherapy for young children with presymptomatic Wilson disease. Such monotherapy proved highly effective and safe. Maintaining normal transaminase values (or values under 50 U/L when normalization is difficult) and 24-h urinary copper excretion between 1 and 3 µg/kg/day and under 75 µg/day is a reasonable goal. An initial dose of 50 mg/day is appropriate for patients under 6 years old.