Compound Heterozygous Mutations in SLC30A2/ZnT2 Results in Low Milk Zinc Concentrations: A Novel Mechanism for Zinc Deficiency in a Breast-Fed Infant.

Zinc concentrations in breast milk are considerably higher than those of the maternal serum, to meet the infant's requirements for normal growth and development. Thus, effective mechanisms ensuring secretion of large amounts of zinc into the milk operate in mammary epithelial cells during lactation. ZnT2 was recently found to play an essential role in the secretion of zinc into milk. Heterozygous mutations of human ZnT2 (hZnT2), including H54R and G87R, in mothers result in low (>75% reduction) secretion of zinc into the breast milk, and infants fed on the milk develop transient neonatal zinc deficiency. We identified two novel missense mutations in the SLC30A2/ZnT2 gene in a Japanese mother with low milk zinc concentrations (>90% reduction) whose infant developed severe zinc deficiency; a T to C transition (c.454T>C) at exon 4, which substitutes a tryptophan residue with an arginine residue (W152R), and a C to T transition (c.887C>T) at exon 7, which substitutes a serine residue with a leucine residue (S296L). Biochemical characterization using zinc-sensitive DT40 cells indicated that the W152R mutation abolished the abilities to transport zinc and to form a dimer complex, indicating a loss-of-function mutation. The S296L mutation retained both abilities but was extremely destabilized. The two mutations were found on different alleles, indicating that the genotype of the mother with low milk zinc was compound heterozygous. These results show novel compound heterozygous mutations in the SLC30A2/ZnT2 gene causing zinc deficiency in a breast-fed infant

Protein-losing enteropathy associated with Henoch-Schönlein purpura

The gastrointestinal manifestations of Henoch-Schönlein purpura include abdominal pain, gastrointestinal bleeding, intussusception, and perforation. Protein-losing enteropathy is rarely associated with Henoch-Schönlein purpura. Two pediatric patients with Henoch-Schönlein purpura who developed protein-losing enteropathy are reported. Tc-99m human serum albumin scintigraphy is useful in the detection of protein-losing enteropathy

Invasive Community-Acquired Methicillin-Resistant Staphylococcus aureus

Pediatric invasive community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection is very serious and occasionally fatal. This infectious disease is still a relatively rare and unfamiliar infectious disease in Japan. We report a positive outcome in a 23-month-old Japanese girl with meningitis, osteomyelitis, fasciitis, necrotizing pneumonia, urinary tract infection, and bacteremia due to CA-MRSA treated with linezolid. PCR testing of the CA-MRSA strain was positive for PVL and staphylococcal enterotoxin b and negative for ACME. SCC mec was type IVa. This case underscores the selection of effective combinations of antimicrobial agents for its treatment. We need to be aware of invasive CA-MRSA infection, which rapidly progresses with a serious clinical course, because the incidence of the disease may be increasing in Japan

Association between cord blood 25-hydroxyvitamin D concentrations and respiratory tract infections in the first 6 months of age in a Korean population: a birth cohort study (COCOA)

PurposePrevious studies suggest that the concentration of 25-hydroxyvitamin D [25(OH)D] in cord blood may show an inverse association with respiratory tract infections (RTI) during childhood. The aim of the present study was to examine the influence of 25(OH)D concentrations in cord blood on infant RTI in a Korean birth cohort.MethodsThe levels of 25(OH)D in cord blood obtained from 525 Korean newborns in the prospective COhort for Childhood Origin of Asthma and allergic diseases were examined. The primary outcome variable of interest was the prevalence of RTI at 6-month follow-up, as diagnosed by pediatricians and pediatric allergy and pulmonology specialists. RTI included acute nasopharyngitis, rhinosinusitis, otitis media, croup, tracheobronchitis, bronchiolitis, and pneumonia.ResultsThe median concentration of 25(OH)D in cord blood was 32.0 nmol/L (interquartile range, 21.4 to 53.2). One hundred and eighty neonates (34.3%) showed 25(OH)D concentrations less than 25.0 nmol/L, 292 (55.6%) showed 25(OH)D concentrations of 25.0-74.9 nmol/L, and 53 (10.1%) showed concentrations of ≥75.0 nmol/L. Adjusting for the season of birth, multivitamin intake during pregnancy, and exposure to passive smoking during pregnancy, 25(OH)D concentrations showed an inverse association with the risk of acquiring acute nasopharyngitis by 6 months of age (P for trend=0.0004).ConclusionThe results show that 89.9% of healthy newborns in Korea are born with vitamin D insufficiency or deficiency (55.6% and 34.3%, respectively). Cord blood vitamin D insufficiency or deficiency in healthy neonates is associated with an increased risk of acute nasopharyngitis by 6 months of age. More time spent outdoors and more intensified vitamin D supplementation for pregnant women may be needed to prevent the onset of acute nasopharyngitis in infants

Autoimmune thyroiditis in antinuclear antibody positive children without rheumatologic disease

<p>Abstract</p> <p>Background</p> <p>Children are commonly referred to a pediatric rheumatology center for the laboratory finding of an Anti-nuclear antibody (ANA) of undetermined significance. Previous studies regarding adult rheumatology patients have supported an association between ANA and anti-thyroid antibodies, with the prevalence of thyroid antibodies being significantly higher in patients referred to a rheumatology center for an ANA without evidence of connective tissue disease compared to the general population. The purpose of the present study was to determine the frequency of thyroid antibodies in children referred to a pediatric rheumatology center for a positive ANA without evidence of a connective tissue disease.</p> <p>Methods</p> <p>A retrospective chart review was performed on children who were referred to our pediatric rheumatology center between August 2003 and March 2007 for positive ANA with concurrent thyroid antibody and thyroid function tests performed who did not fulfill criteria for a specific connective tissue disease. Laboratory and clinical features were recorded and analyzed. Mean and standard deviation were used to describe continuous data. Chi-square or Fisher's exact tests were used to compare proportions between variables.</p> <p>Results</p> <p>One-hundred and four ANA-positive patients with concurrent thyroid studies were evaluated (88% female, 93% Caucasian, mean age 11.9 ± 4.0 years). Half of patients had an ANA titer ≥ 1:320. The ANA pattern was speckled in 60% of the patients. Thyroid antibodies were detected in 30% of the patients. Anti-Thyroglobulin (ATG) was detected in 29% and Anti-thyroid peroxidase (ATPO) in 21% of the patients; of these children, 14% had hypothyroidism. ANA pattern and titer were not associated with anti-thyroid antibody positivity.</p> <p>Conclusion</p> <p>Thyroid antibodies associated with chronic lymphocytic thyroiditis, ATG and ATPO, were detected significantly higher in ANA-positive children without a rheumatologic condition (30%) as compared to the general pediatric population (1.3 - 3.4%). ANA titer and pattern did not help predict the presence or absence of thyroid antibodies. Given the high frequency of thyroid antibodies and increased risk of developing hypothyroidism over time, routine evaluation of ATG and ATPO with thyroid function tests in ANA-positive children is recommended.</p

Phenotypic characteristics of F64L, I68L, I107V, and S77Y ATTRv genotypes from the Transthyretin Amyloidosis Outcomes Survey (THAOS)

Transthyretin amyloidosis (ATTR amyloidosis) is a progressive, multi-systemic disease with wild-type (ATTRwt) and hereditary (ATTRv) forms. Over 130 variants associated with ATTRv amyloidosis have been identified, although little is known about the majority of these genotypes. This analysis examined phenotypic characteristics of symptomatic patients with ATTRv amyloidosis enrolled in the Transthyretin Amyloidosis Outcomes Survey (THAOS) with four less frequently reported pathogenic genotypes: F64L (c.250T&gt;C, p.F84L), I68L (c.262A&gt;T, p.I88L), I107V (c.379A&gt;G; p.I127V), and S77Y (c.290C&gt;A; p.S97Y). THAOS is the largest ongoing, global, longitudinal observational study of patients with ATTR amyloidosis, including both ATTRwt and ATTRv amyloidosis. This analysis describes the baseline demographic and clinical characteristics of untreated symptomatic patients with the F64L, I68L, I107V, or S77Y genotypes at enrollment in THAOS (data cutoff date: January 4, 2022). There were 141 symptomatic patients with F64L (n = 46), I68L (n = 45), I107V (n = 21), or S77Y (n = 29) variants at the data cutoff. Most patients were male and median age at enrollment was in the sixth decade for S77Y patients and the seventh decade for the others. A predominantly neurologic phenotype was associated with F64L, I107V, and S77Y genotypes, whereas patients with the I68L genotype presented with more pronounced cardiac involvement. However, a mixed phenotype was also reported in a considerable proportion of patients in each variant subgroup. This analysis from THAOS represents the largest study of ATTRv symptomatic patients with the F64L, I68L, I107V, and S77Y genotypes. These data add to the limited knowledge on the clinical profile of patients with specific ATTRv variants and emphasize the importance of comprehensive assessment of all patients