以先天性甲状腺功能减退为首发症状的假性甲状旁腺功能 减退症临床家系分析

目的探讨假性甲状旁腺功能减退症(PHP)Ia型的发病机制、临床特点及治疗。方法回顾分析1例PHP Ia型患儿及其家族成员的临床及遗传学资料。结果患儿以先天性甲状腺功能减退为首发症状,后逐渐表现出Albright遗传性骨营养不良症(AHO)、低钙、高磷、对甲状旁腺激素抵抗的症状,给予骨化三醇及钙剂治疗后,血钙、磷接近正常,但AHO畸形无明显变化。结论 PHP合并先天性甲状腺功能减退较为罕见。     

儿童遗传性甲状旁腺功能减退

甲状旁腺素分泌减少或激素抵抗都会导致功能不足的症状,分别称之为甲状旁腺功能减退（HP）和假性甲状旁腺功能减退（PHP）,两者均表现为低钙血症,多伴有高磷血症。HP分为获得性和遗传性两大类,成人基本为获得性,而儿童发病率低,多由遗传变异导致。PHP则一般和GNAS基因变异相关,属于遗传罕见病,类型多,临床表现变异大,诊断需要结合临床表现和遗传检测。HP和PHP的主要治疗都是针对低钙血症补充钙剂和活性维生素D,治疗期间要监测肾钙质沉着。同时PHP还需要关注其他激素抵抗和Albright’s骨营养不良（Albright’s hereditary osteodystrophy,AHO）的症状,予以相应的随访和治疗。     

GNAS 基因新生突变致假性甲状旁腺功能减退症Ia 型1 例

目的鉴定导致假性甲状旁腺功能减退症(PHP)Ia型发病的GNAS基因突变。方法回顾分析1例PHP-Ia型患儿的临床资料。利用Sanger测序方法对患儿及其父母GNAS基因的13外显子进行检测。疑似致病突变在478例健康对照者中进行筛查,排除非致病性变异。利用深度测序方法对患儿及其父母外周静脉血的DNA进行测序,分析确定致病突变的起源。结果女性患儿,实验室检查结果示低血钙、高血磷及高甲状旁腺素(PTH);体格检查有Albright遗传性骨营养不良(AHO)畸形。临床表现符合PHP-Ia型特征。GNAS基因突变筛查发现1个尚未见报道的,位于6号外显子的错义突变(c.479GC,p.R160P)。父母及健康对照均者未发现该突变。针对突变所在的GNAS基因6号外显子在患儿及其父母外周静脉血的DNA中进行深度测序,每个样本均获得8 000条左右的序列。患儿父母的所有序列中均筛查到该突变。患儿序列中,3 984条携带G等位基因,4 019条携带C等位基因,两者的数目大致相同。深度测序的结果提示,该突变是来源于母系生殖细胞的新发突变。结论发现一个导致PHP-Ia型发生的GNAS基因新突变(c.479GC,p.R160P),推测该突变起源于母亲生殖细胞。     

假性甲状旁腺机能减退症4例临床分析

目的提高对假性甲状旁腺机能减退症(PHP)的认识、诊断及治疗。方法中国医科大学附属第一医院2007年4月至2008年4月对4例(男3例、女1例)因四肢麻木或间断抽搐为主诉的11~14岁患儿进行血钙、血磷、甲状旁腺激素(PTH)及头部CT等项检查,并进行综合分析。结果4例患儿中呈PHP典型面容和体态者2例、表型正常2例。4例血钙明显下降、血磷高、PTH水平高,补钙治疗不见好转。结论PHP是PTH受体缺陷性疾病,临床少见,当患儿出现四肢麻木及反复抽搐、血钙低时,无论表型是否正常都要想到本病。血钙低、血磷高、血PTH升高是诊断PHP的必要条件。     

努南综合征20例临床及遗传学分析

目的分析儿童努南综合征的临床及遗传学特征。方法回顾性分析2016年3月至2020年12月首都医科大学附属北京儿童医院内分泌遗传代谢科诊断的20例努南综合征患儿的临床病例、遗传学分析及随访资料。结果 20例努南综合征患儿中男13例、女7例, 诊断年龄5.9(1.1～12.2)岁。首诊主诉身高增长缓慢17例, 尿道下裂或隐睾2例, 特殊面容1例。体格检查发现努南综合征典型面容12例, 隐睾、小阴茎、尿道下裂9例, 心脏结构异常10例, 智力发育迟缓10例。PTPN11基因变异12例, SOS2基因变异 4例, SHOC2及SOS1基因变异各2例。6例患儿接受重组人生长激素治疗, 治疗9个月时身高不同程度的增长4.0(2.5～6.0)cm, 暂无不良事件的发生。结论努南综合征中男性患儿多见外生殖器异常。基因变异频率除PTPN11变异为主外, SOS2基因变异较高, 均以新发变异为主。不同首诊科室获得的综合征表型谱有差异, 了解综合征的全貌需要采集不同科室就诊信息。     

HDAC8基因变异所致Cornelia de Lange综合征1例报告

目的探讨Cornelia de Lange综合征(CdLS)的临床表型及基因型特点。方法回顾分析1例确诊CdLS患儿的临床资料,并总结分析国内已报道病例的情况。结果女性患儿,1岁2月龄,有特殊外貌,智力及运动发育落后,合并四肢畸形及听力异常。基因检测发现患儿HDAC8基因c.675C>A(p.Y 225X)存在新发杂合无义变异,根据ACMG指南预测为致病性变异,确诊CdLS。通过对万方、维普、中国知网及PubMed数据库搜索,发现国内报道CdLS病例46例。其中26例行基因检查,20例(76.9%)存在NIPBL基因变异,3例(11.5%)HDAC8基因变异,1例(3.8%)SCM1A基因变异,2例未发现与临床吻合的致病性基因变异,表型各异。结论CdLS患儿存在特殊外貌、生长发育迟缓、多器官受累、听力障碍,多数可通过典型临床表型诊断,基因检测有助于非典型患者的早期诊断。     

新疆地区维吾尔族成骨不全九例患儿基因型与表型分析

目的探讨新疆地区维吾尔族儿童成骨不全基因变异谱系及临床表型特点.方法回顾性分析2013年1月至2017年12月新疆医科大学第一附属医院儿科就诊的9例(男4例、女5例)维吾尔族成骨不全患儿的临床资料,按照经典Sillence分型进行临床分型.检测成骨不全相关基因,利用美国医学遗传学和基因组学协会指南、InterVar、Alamut功能软件评估变异致病性,分析基因变异谱系特点.结果9例患儿年龄3岁6月龄~15岁,临床表现为反复骨折、骨骼畸形、矮小、蓝巩膜、听力异常、牙本质发育不全、关节韧带松弛.其中成骨不全Ⅲ型6例、Ⅳ型3例.9例患儿中共发现3种基因(COL1A1、COL1A2和SERPINF1)的9个候选变异,其中5个变异位点为国际首次报道,经评估均为可能致病性变异.结论新疆维吾尔族成骨不全临床表型复杂多样,但均有骨折及骨骼畸形.基因型与国内外报道有差异,SERPINF1基因可能在维吾尔族人群中更为高发,维吾尔族成骨不全的遗传异质性及独特的基因变异谱系,进一步为成骨不全的基因型与表型相关性提供了依据.     

新生儿糖尿病的诊治思路

新生儿糖尿病（neonatal diabetes mellitus，NDM）是一种罕见的单基因病，临床表现隐匿，临床表型与基因型异质性大，容易延误诊断。近年来，随着基因检测技术的发展，越来越多的致病基因逐渐被认识，目前已知的有30多种基因变异可引起NDM，不同亚型的NDM在临床表现、治疗和转归等方面有所不同。染色体6q24印记区域的基因变异或甲基化异常是暂时性新生儿糖尿病（transient neonatal diabetes mellitus，TNDM）最常见的原因，ATP敏感性钾通道(K_ATP)基因（KCNJ11、ABCC8）变异是持续性新生儿糖尿病（persistent neonatal diabetes mellitus，PNDM）的最常见原因。NDM常需胰岛素替代治疗，而大约90%的KCNJ11或ABCC8变异的NDM患儿口服磺脲类药物治疗可维持稳定血糖水平，早期治疗还可逆转部分KCNJ11变异导致的神经发育迟缓，同时可增加从胰岛素转换至磺脲类药物治疗的成功率。早期明确遗传学诊断和分型有助于实现精准个体化治疗，判断预后。本文就NDM的基因型-临床表型及治...     

合并围生期缺氧的新生儿脑病遗传因素分析

目的探讨合并围生期缺氧的新生儿脑病遗传因素。方法收集2016年1月至2019年1月参与复旦大学附属儿科医院"新生儿基因组计划"的133例新生儿。纳入标准为诊断为新生儿脑病、合并围生期急性缺氧事件或Apgar评分≤7分的患儿。回顾性分析患儿临床表现、脑电图及头颅影像学表现、基因测序结果和转归等。结果 133例患儿中男77例(57.9%),女56例(42.1%);剖宫产出生56例(42.1%),自然出生77例(57.9%);其中诊断为新生儿缺氧缺血性脑病的患儿68例(51.1%),颅内出血25例(18.8%),遗传学病因的20例(15.0%),败血症(未合并颅内感染)5例(3.8%)。20例二代测序结果阳性的遗传学病因患儿中,19例明确致病性,1例为意义不明;分别为 4例先天性肌病相关变异基因(MTM1基因变异2例、ACTA1基因变异和RYR1基因变异各1例),4例综合征相关变异基因(CHD7基因变异2例、PTN11和NSDHL基因变异各1例),3例代谢性疾病相关变异基因(OTC、MTHFR、ALDH7A1基因变异各1例),2例癫痫性脑病相关变异基因(KCNT1和PACS2基因变异各1例),1例为呼吸中枢相关变异基因(PHOX2B基因变异)以及6例拷贝数致病变异。20例遗传学病因患儿中,8例(40.0%)肌张力减低,7例(35.0%)惊厥,5例(25.0%)合并畸形;20例患儿或家庭均进行遗传咨询,4例患儿死亡,10例患儿放弃治疗出院,6例患儿经过对症支持治疗后症状缓解,出院后进一步制定专科随访计划。结论在合并围生期缺氧的新生儿中,遗传学病因并不少见。先天性肌病、综合征类、代谢性疾病和癫痫性脑病相关变异基因为常见遗传学病因。     

MTOR基因变异致Smith-Kingsmore综合征2例并文献复习

目的总结MTOR基因变异致Smith-Kingsmore综合征的临床表型及遗传学特点。方法回顾性分析2018年4月至2021年4月在西安市儿童医院明确诊断的2例MTOR基因变异致Smith-Kingsmore综合征患儿的临床资料。以"MTOR"和"Smith-Kingsmore"为关键词分别在中国期刊全文数据库(CNKI)、万方数据知识服务平台、PubMed、OMIM进行检索(建库至2021年8月), 总结MTOR基因变异特点及其导致Smith-Kingsmore综合征患儿的临床特点。结果 2例患儿均为女性, 分别为1岁6月龄和2岁, 发病年龄均在婴儿期, 均表现为全面发育迟缓、巨头畸形及面容异常, 全外显子基因检测均发现MTOR基因新发杂合变异, 1例携带c.5395G>A(p.Glu1799Lys), 另1例携带c.7234G>C(p.Asp2412His)。文献检索未见中文文献, 国外文献报道具有详细表型的MTOR基因变异致Smith-Kingsmore综合征患者45例, 共发现11个基因变异, 均为杂合错义变异, 28例(62%)患者携带c.5395G>A(p...     

Molecular analysis of the GNAS1 gene for the correct diagnosis of Albright hereditary osteodystrophy and pseudohypoparathyroidism

Pseudohypoparathyroidism (PHP) is a heterogeneous disease characterized by PTH resistance and classified as types Ia, Ib, Ic, and II, according to its different pathogenesis and phenotype. PHP-Ia patients show Gsalpha protein deficiency, PTH resistance, and typical Albright hereditary osteodystrophy (AHO). Heterozygous mutations in the GNAS1 gene encoding the Gsalpha protein have been identified both in PHP-Ia and in pseudopseudohypoparathyroidism (PPHP), a disorder with isolated AHO. A single GNAS1 mutation may be responsible for both PHP-Ia and PPHP in the same family when inherited from the maternal and the paternal allele, respectively, suggesting that GNAS1 is an imprinted gene. To evaluate whether molecular diagnosis is a useful tool to characterize AHO and PHP when testing for Gsalpha activity and PTH resistance is not available, we have performed GNAS1 mutational analysis in 43 patients with PTH resistance and/or AHO. Sequencing of the whole coding region of the GNAS1 gene identified 11 mutations in 18 PHP patients, eight of which have not been reported previously. Inheritance was ascertained in 13 cases, all of whom had PHP-Ia: the mutated alleles were inherited from the mothers, who had AHO (PPHP), consistent with the proposed imprinting mechanism. GNAS1 molecular analysis confirmed the diagnosis of PHP-Ia and PPHP in the mutated patients. Our results stress the usefulness of this approach to obtain a complete diagnosis, expand the GNAS1 mutation spectrum, and illustrate the wide mutation heterogeneity of PHP and PHP-Ia.     

Pseudohypoparathyroidism type 1a with congenital hypothyroidism

Pseudohypoparathyroidism type la (PHP-1a) is an uncommon disorder that results from an inactivating mutation in the GNAS gene. It can present with resistance to several hormones, in addition to parathyroid hormone (PTH). Patients may have the classic Albright's hereditary osteodystrophy (AHO) phenotype and can develop resistance to thyroid stimulating hormone (TSH), gonadotropins, growth hormone releasing hormone (GHRH), and other hormones that rely on the Gsalpha protein to regulate signal transmission at their receptors. We report two siblings with PHP-1a and congenital hypothyroidism. The patients were found to have a heterozygous mutation at nucleotide 305 in exon 4 (c305C-->A) of the GNAS gene, which has not been previously linked to congenital hypothyroidism.     

Determination of Gs alpha protein activity in Albright's hereditary osteodystrophy

Albright's hereditary osteodystrophy (AHO) is a heterogeneous clinical entity in part associated with pseudohypoparathyroidism (PHP) and other endocrinopathies. It may be caused by diminished Gs alpha protein activity. Heterozygous mutations in the underlying GNAS gene on chromosome 20 have been described. One hundred and six patients with suspected AHO, were investigated, of whom 93 showed a laboratory profile of PHP with low or normal calcium and elevated parathormone with normal vitamin D metabolites, and 13 had no endocrine abnormalities. Gs alpha activity was determined in isolated erythrocyte membranes. Molecular genetic analysis of GNAS exons 2-13 was initiated. Significantly reduced Gs alpha activity was found in 91 patients. In 53 patients with reduced Gs alpha activity, a mutation within GNAS was demonstrated. The mutation detection rate was much lower in AHO patients without endocrinopathies than in those who had PHP. In addition, three of the 15 patients with AHO features but normal Gs alpha activity had genetic variations of GNAS. We conclude that determination of Gs alpha activity can be used as a diagnostic screening procedure in patients with suspected AHO. However, the mutation detection rate in GNAS is highly variable. The genetic heterogeneity of AHO needs further investigation.     

Different expression of the Asn264LysfsX35 mutation of the GNAS gene in a family with pseudohypoparathyroidism.

Pseudohypoparathyroidism (PHP) is a heterogeneous group of endocrine diseases characterised by hypocalcaemia, hyperphosphataemia and resistance to PTH. There are different forms of PHP. PHP-Ia is the most frequent form and shows multi-hormonal resistance, GNAS (Gs_α) mutations and signs of Albright?s hereditary osteodystrophy (AHO). PseudoPHP (PPHP) have isolated AHO without hormonal resistance and it is also caused by GNAS mutations. We present a family that share the same inactivating GNAS mutation (Asn264LysfsX35); the mother being affected with PPHP and the two daughters with PHP-Ia. We discuss the different clinical phenotypes and the dominant mode of inheritance with genetic imprinting where the phenotype of the offspring depends on the sex of the parent affected.     

Hormone resistance caused by mutations in G proteins and G protein-coupled receptors

G proteins couple receptors for many hormones to effectors that regulate second messenger metabolism. Several endocrine disorders have been shown to be caused by either loss or gain of function mutations in G proteins or G protein-coupled receptors. Pseudohypoparathyroidism (PHP), the first described example of a hormone resistance disorder, is characterized by renal resistance to parathyroid hormone (PTH) proximal to generation of the second messenger, cAMP. In PHP Ia there is more generalized hormone resistance (PTH, TSH, gonadotropins) and associated abnormal physical features, Albright hereditary osteodystrophy (AHO). Subjects with PHP Ib are normal in appearance and resistant exclusively to PTH. Germline loss of function mutations have been identified in the Gs-alpha gene in PHP Ia, and recent evidence suggests that the Gs-alpha gene is paternally imprinted in a tissue-specific manner. In PHP Ib, several studies have excluded PTH receptor gene mutations, and the molecular basis has not yet been defined.     

Two teenage males with hypocalcemia and elevated parathyroid hormone levels

Vitamin D deficiency is not a rare disorder, particularly in minority groups. The Institute of Medicine recommends serum 25-hydroxyvitamin (OH)D levels >20 ng/mL and The Endocrine Society recommends levels >30 ng/mL for good health. In contrast, the 2003-2006 National Health and Nutrition Examination Survey reported average total 25-(OH)D concentrations of 25.6 ± 0.4 ng/mL in whites, 19.5 ± 0.5 ng/mL in Mexican Americans, and 14.8 ± 0.4 ng/mL in blacks. Pediatric patients with vitamin D deficiency may be asymptomatic or may present either with rickets, hypocalcemia, or seizures.Pseudohypoparathyroidism (PHP) is a rare disorder characterized by parathyroid hormone (PTH) resistance with (type 1a) or without (type 1b) the Albright Hereditary Os-teodystrophy (AHO) phenotype of short stature, brachydactyly, and mental retardation. Patients with PHP have elevated PTH levels and may have hyperphosphatemia and hypocalcemia. However, the same laboratory values can be seen in children with vitamin D deficiency, and diagnostic confusion is common. We report two cases of vitamin D deficiency with presentations suggestive of PHP.     

Mutational analysis of the GNAS1 exons encoding the stimulatory G protein in five patients with pseudohypoparathyroidism type 1a

We analyzed the GNAS1 gene in five patients with pseudohypoparathyroidism type 1a (PHP1a) by performing polymerase chain reaction, followed by sequencing all 13 exons of the gene, single-stranded conformational polymorphism (SSCP) or heteroduplex analysis (HD). Three novel mutations were discovered: (1) a de novo 3 bp insertion of CTG in codon 47 of exon 1; (2) a missense mutation 1103T in exon 4; and (3) a de novo mutation of Arg280Gly in exon 10. Two other mutations, previously described in the literature, include: (1) a de novo 4 bp deletion (deltaGACT) involving codons 189 and 190 in exon 7, and (2) a deletion of a cytosine nucleotide at codon 115 in exon 5. We conclude that mutational analysis of the GNAS1 gene is a strong supportive tool for the diagnosis of PHP1a, and is a useful adjunct to the synthetic parathyroid hormone infusion test for PTH resistance.