SLC12A3 基因新突变致Gitelman 综合征一家系报告

目的探讨Gitelman综合征的基因诊断。方法回顾性分析1例Gitelman综合征患儿的临床资料,及患儿与其父母、姐姐的基因分析结果。结果患儿,男,6岁。因发热、低血钾入院。经检测发现SLC12A3基因位点EXON 21c.2522AG p.(Asp841Gly)杂合宽度和EXON16 c.1946CT p.(Thr649Met)杂合突变,确诊为Gitelman综合征。患儿母亲携带EXON21 c.2522AG p.(Asp841Gly)杂合,患儿父亲和姐姐携带EXON16 c.1946CT p.(Thr649Met)杂合突变。结论SLC12A3基因检测有助于Gitelman综合征诊断,新发现SLC12A3基因突变丰富了Gitelman综合征基因突变谱。     

Bartter syndrome in two siblings--antenatal and neonatal observations

Bartter syndrome was diagnosed in two siblings born to healthy unrelated parents. Each pregnancy was complicated by severe polyhydramnios. The first child was treated with indomethacin from the age of then weeks on. At the age of six years he is doing very well: height is 109.9 cm (P3) and weight 17.8 (P3). Studies of the amniotic fluid during the mother's second pregnancy showed high chloride concentrations (112, 117, and 119 mEq/l), normal levels of sodium, potassium, calcium and creatinine and low prostaglandin E2 (5.0-22.3 pg/ml) and F2 alpha (36-71.7 pg/ml) concentrations. Severe chloride and sodium wasting after birth resulted in hypochloremia, hyponatremia and dehydration. Concomitantly an immediate and striking increase in urinary PGE2 excretion from 45 to 1022 pg/ml was observed. Indomethacin therapy had to be stopped after one week when necrotising enterocolitis developed.     

A novel single point mutation of the LYST gene in two siblings with different phenotypic features of Chediak Higashi syndrome

Chediak Higashi syndrome (CHS) is an autosomal-recessive disorder characterized by oculocutaneous albinism, recurrent infections and a progressive primary neurological disease. Here, we describe two siblings with CHS due to a novel homozygous R1836X mutation in the LYST gene associated with loss of NK cell degranulation and cytotoxicity. While one sibling was born with fair skin and hair and died of hemophagocytic lymphohistiocytosis (HLH) at 5 months of age, the other sibling had dark black hair and skin and developed HLH at the age of 4 years.     

Genotypic/phenotypic heterogeneity of selective vitamin B12 malabsorption (Grasbeck-Imerslund syndrome) in two Bedouin families

We report on seven patients in two unrelated consanguineous Bedouin families with Grasbeck-Imerslund syndrome. Pedigree analysis in Family 1 was suggestive of an X-linked mode of inheritance. Intra- and interfamilial heterogeneity was elicited among the affected children in both families. Two of the affected sibs in each family had raised Hb A2 (>4%) while a third in Family 1 had a raised level of Hb F before treatment. One of the patients developed subacute combined degeneration of the cord at the age of 17 years before the correct diagnosis was made. All abnormalities were corrected following the institution of parenteral cobalamin therapy.     

Expanding the spectrum of genetic mutations in antenatal Bartter syndrome type II

Bartter syndrome (BS) is a group of genetic disorders characterized by hypokalemic metabolic alkalosis, hyponatremia and elevated renin and aldosterone plasma concentrations. BS type II is caused by mutations in the KCNJ1 gene and usually presents with transient hyperkalemia. We report here a novel KCNJ1 mutation in a male neonate, prematurely born after a pregnancy complicated by polyhydramnios. The infant presented with typical clinical and laboratory findings of BS type II, such as hyponatremia, hypochloremic metabolic alkalosis, severe weight loss, elevated renin and aldosterone levels and transient hyperkalemia in the early postnatal period, which were later normalized. Molecular analysis revealed a compound heterozygous mutation in the KCNJ1 gene, consisting of a novel K76E and an already described V315G mutation, both affecting functional domains of the channel protein. Typical manifestations of antenatal BS in combination with hyperkalemia should prompt the clinician to search for mutations in the KCNJ1 gene first.     

Pathologic features in two siblings with the Pena-Shokeir I syndrome

Two siblings whose clinical and pathologic features were consistent with the Syndrome of camptodactyly, multiple ankyloses and pulmonary hypoplasia originally described by Pena and Shokeir were examined at autopsy. Additional features were intrauterine growth retardation, immaturity of the central nervous system (CNS) and atrophy of skeletal muscles. Our data suggest that CNS damage may cause the complicated phenotypic abnormalities of the syndrome.Abbreviations CNS central nervous system - IUGR intrauterine growth retardation - COFS cerebro-oculo-facio-skeletal     

Simultaneous development of pheochromocytomas in prepubertal siblings with von Hippel-Lindau syndrome

We report 2 siblings with a known von Hippel-Lindau mutation who simultaneously developed asymptomatic pheochromocytomas at significantly younger ages than are typically seen in this setting.     

Enteroinsular hormones in two siblings with Donohue syndrome and complete leptin deficiency

The main biochemical hallmark of the rare and lethal condition of Donohue syndrome (DS) is hyperinsulinemia. The roles of the gut and other pancreatic hormones involved in glucose metabolism, satiety and energy expenditure have not been previously reported in DS. Two siblings with genetically confirmed DS and extremely low weight underwent a mixed meal (MM) test where pancreatic hormones insulin, C‐peptide, glucagon, active amylin, pancreatic polypeptide (PP) as well as gut hormones active glucagon‐like peptide 1 (GLP‐1), glucose‐dependent insulinotropic peptide (GIP), ghrelin, peptide YY (PYY) and leptin were analyzed using a Multiplex assay. Results were compared to those of 2 pediatric controls. As expected, concentrations of insulin, C‐peptide and amylin were very high in DS cases. The serum glucagon concentration was undetectable at the time of hypoglycemia. GIPs concentrations were lower in the DS, however, this was not mimicked by the other incretin, GLP‐1. Ghrelin concentrations were mainly undetectable (<13.7 pg/mL) in all participants. DS cases had higher PYY and dampened PP concentrations. Leptin levels remained completely undetectable (<137.0 pg/mL). Patients with DS have extremely high amylin levels, completely undetectable serum glucagon and leptin levels with abnormal satiety regulating hormone PP with a relatively normal ghrelin response during a MM test. The low serum GIP might be acting as physiological brake on insulin secretion. The undetectable serum leptin levels suggest the potential of using leptin analogues as therapy for DS patients.     

Thiamine responsive megaloblastic anemia: a novel SLC19A2 compound heterozygous mutation in two siblings

Thiamine responsive megaloblastic anemia (TRMA) is an autosomal recessive disease caused by loss of function mutations in the SLC19A2 gene. TRMA is characterized by anemia, deafness, and diabetes. In some cases, optic atrophy or more rarely retinitis pigmentosa is noted. We now report two sisters, the eldest of which presented to a different hospital during childhood with sensorineural deafness, which was treated with a hearing prosthesis, insulin requiring diabetes, retinitis pigmentosa, optic atrophy, and macrocytic anemia. These features initially suggested a clinical diagnosis of Wolfram syndrome (WS). Therapy with thiamine was initiated which resulted in the resolution of the anemia. The younger sister, who was affected with sensorineural deafness, was referred to our hospital for non‐autoimmune diabetes. She was found to have macrocytosis and ocular abnormalities. Because a diagnosis of TRMA was suspected, therapy with insulin and thiamine was started. Sequencing analysis of the SLC19A2 gene identified a compound heterozygous mutation p.Y81X/p.L457X (c.242insA/c.1370delT) in both sisters. Non‐autoimmune diabetes associated with deafness and macrocytosis, without anemia, suggests a diagnosis of TRMA. Patients clinically diagnosed with WS with anemia and/or macrocytosis should be reevaluated for TRMA.     

Medium-chain acyl-CoA dehydrogenase deficiency in two siblings with a Reye-like syndrome

An increasing number of reports indicate that patients with some inherited metabolic diseases may have symptoms resembling those of Reye syndrome. We describe two siblings who developed a Reye-like syndrome at ages 16 and 18 months, respectively, after a viral illness and salicylate therapy. Both had fasting hypoglycemia and hypoketonemia. At the time of the acute episode and after ingestion of a medium-chain triglyceride load, one of them excreted large amounts of abnormal metabolites derived from the omega- and (omega-1)-oxidation of medium-chain fatty acids. Medium-chain acyl-CoA dehydrogenase activity was lower than 20% of control values in fibroblasts from both patients. This enzyme defect should be considered in children with a Reye-like syndrome with these distinctive manifestations.     

两种新型Wiskott-Aldrich综合征蛋白基因突变的鉴定

目的 明确3例Wiskott-Aldrich综合征(WAS)患儿WAS蛋白(WASP)基因突变的类型。方法 根据典型临床表现(血小板减少、湿疹、反复感染),及淋巴细胞和血小板扫描电镜改变,采用PCR直接测序法,对3例疑为WAS的患儿及其母亲的WASP基因进行序列分析。结果 以正义、反义引物扩增的PCR产物分别测序,发现两种新型WASP基因突变：2例WAS孪生兄弟WASP基因第10外显子,第984位核苷酸C缺失突变(984delC),导致317位密码子后移码突变,于444位密码子提前出现终止密码(H317fsX444);其母亲为此突变WASP基因携带者。另l例WAS患儿WASP基因第ll外显子,第1388位核苷酸由G替换为T(1388G→T),为无义突变,使第452位密码子提前变为终止密码(E452X)。其母亲无此突变WASP基因。结论 鉴定出两种新型WASP基因突变,WASP基因序列分析对于不典型和散发WAS的诊断及WASP突变基因携带者的检出有重要作用。     

脑肌酸缺乏综合征Ⅰ型两家系临床特征及SLC6A8基因变异分析

该文报道2例由SLC6A8基因变异导致的脑肌酸缺乏综合征Ⅰ型（CCDS1）的临床及遗传学特征。2例患儿均为男性,年龄分别为2岁10个月、8岁11个月,主要表现为精神运动发育落后、抽搐。均有一哥哥出现类似症状,患儿1母亲轻度智力低下。经家系基因分析发现X染色体上SLC6A8基因分别存在c.200G > A（p.Gly67Asp）和c.626_627delCT（p.Pro209Argfs^*87）变异,变异均来自患儿母亲。这2个变异分别评级为可能致病性变异、致病性变异,既往未见文献报道。该研究拓展了SLC6A8基因突变谱,对精神运动发育落后、癫痫的男性患者的诊断具有重要意义。