X-连锁肾上腺脑白质营养不良ABCD1基因突变分析

目的对5例X-连锁肾上腺脑白质营养不良（X-ALD）患儿及其中2例的母亲进行ABCD1基因突变分析。方法聚合酶链反应（PCR）扩增5例X-ALD患儿ABCD1基因的10个外显子及其侧翼序列,直接进行测序。将测序结果与正常ABCD1基因序列比对,确定突变位点和突变形式。同时测定30例健康儿童ABCD1基因序列以明确突变位点是否为基因多态性。结果伴ABCD1基因突变3例,1例为外显子6上518位氨基酸的点突变,为Arg518Gly（CGG→GGG）;2例为外显子1上8个碱基缺失（134del8）。同时在外显子7上发现4个位点的基因多态性,分别为Gly551X（GGC→GGT）、Arg554His（CGT→CAT）、Gln567Arg（CAA→CGA）和Val582Ile（GTC→ATC）。2例患儿的母亲均未检测到突变。结论3例X-ALD患儿证实存在ABCD1基因突变,其中外显子1的8个碱基的缺失（134del8）为新发现的突变;新发现中国人外显子7的4个位点基因多态性,分别为Gly551X、Arg554His、Gln567Arg和Val582Ile。     

家族性高胆固醇血症低密度脂蛋白受体基因突变的研究

目的 分析中国儿童家族性高胆固醇血症低密度脂蛋白受体基因突变,并建立筛查该基因突变的方法。方法 以一家两患儿及其父母的基因组DNA为模板,用聚合酶链反应（PCR）及增该基因的启动子和全部18个外显子。用温度梯度凝胶电泳（TGGE）分析检测PCR产物,对电泳结果异常者进行DNA测序。结果 平行TGGE发现,两患儿第13外显子存在一纯合突变,其父母此外显存在杂合突变。DNA测充证实两患儿第13外显子发生Ala^606→Thr纯合错义突变,其父母均为此Ala^606→Thr杂合突变。结论 此家系家族性高胆固醇血症患者的LDL受体 基因存在Ala^606→Thr突变。TGGE结合DNA测序法的建立可用本症的基因诊断。     

CITED2基因突变与先天性心脏病关系研究

目的 研究CITED2基因突变与先天性心脏病（CHD）的关系。方法 2013年1月至2015年1月山东大学齐鲁儿童医院收集368例散发型CHD患儿和200名健康儿童血液样本进行DNA抽提, PCR扩增CITED2外显子区, Sanger测序后, 进行GeneBank对比和氨基酸序列分析。结果 发现4例杂合突变。病例1室间隔缺损患儿为c.399C＞T同义突变（p.His133His）; 病例2室间隔缺损患儿为SGJ区c.574A＞G的错义突变（p.Ser192Gly）; 病例3房间隔缺损患儿为已知 SNP位点（rs191856368）; 病例4动脉导管未闭患儿为新发现的错义突变（p.Ser96Phe）。这些突变在对照组中均未检测到。结论 CITED2基因Ser192Gly和p.Ser96Phe突变可能与CHD发生有关。     

软骨发育不全一家系成纤维细胞生长因子受体3基因G1138A 突变研究北大核心CSCD

目的：检测和分析一先天性软骨发育不全（ACH）家系4人成纤维细胞生长因子受体3（FGFR3）基因突变位点,并观察重组人生长激素（rhGH）对 ACH 患儿身高的改善作用。方法采集该家系成员4人外周血样本,应用 PCR-DNA 测序方法,对该家系各成员 FGFR3基因第10号外显子的核苷酸序列进行测定,并对先证者给予 rhGH[0.15 U/（kg＆#183;d）]治疗。结果 DNA 测序显示该家系中患儿-患儿母亲及患儿姐姐 FGFR3基因第10号外显子上均发生 c.1138G ﹥ A 杂合突变,使得其所编码蛋白 FGFR3的第380位氨基酸由甘氨酸变为精氨酸,其父亲第10号外显子未发生突变;给予 rhGH 治疗6个月,先证者身高增加了3.8 cm。结论FGFR3基因跨膜区1138位核苷酸 G ﹥ A 转换突变是该 ACH 家系的主要发病原因,说明了该突变为热点突变。在该家系中,先证者母亲表现为新发突变,然后遗传给其2个女儿。rhGH 对 ACH 患者的身高增长近期疗效较好。     

RBM20 基因新发错义突变致家族性儿童扩张性心肌病 1 例报告

目的探讨儿童扩张性心肌病的临床特点及基因特征。方法分析1例儿童扩张性心肌病患儿的临床资料和基因检测结果,并复习相关文献。结果男性患儿,11岁,活动后气促、心悸,心脏彩超提示左心室、左心房明显扩大,左室射血分数35%,左室短缩分数20%。基因检测结果显示,患儿及母亲RBM20基因9号外显子出现杂合突变c.2264GA,p.Arg 755 His,11号外显子也出现杂合突变c. 3014 A G,p.Asp 1005 Gly,均为错义突变,以前均未见报道。结论儿童家族性扩张性心肌病诊断主要通过临床和基因检测。     

甘露糖结合凝集素基因多态性与幼年特发性关节炎的相关性

目的 探讨甘露糖结合凝集素（MBL）基因外显子1多态性与幼年特发性关节炎（JIA）易感性的关系。方法 采用聚合酶链反应．限制性片段长度多态性（PCR，RFLP）法分析93例JIA和48名正常健康儿童MBL基因外显子1第54和57位密码子的多态性。结果 1．JIA及健康儿童均未发现有57位密码子突变。2．JIA患儿第54位密码子野生型基因型频率为71．0％（66／93），杂合子型为25.8％（24／93），突变纯合子型为3．2％（3／93）；正常对照儿童野生型75．0％（36／48），杂合子型为25．0％（12／48），未发现突变纯合子基因型；各基因型与JIA组比较无差异（P〉0．05）。结论 MBL基因外显子1多态性与JIA无相关。     

儿童神经母细胞瘤中ALK基因突变的研究

目的：探讨中国儿童神经母细胞瘤（NB）中间变性淋巴瘤激酶（ALK）基因的突变情况。方法：从22例石蜡包埋的NB肿瘤组织中提取基因组DNA,通过PCR-DNA直接测序技术分析儿童NB肿瘤组织中ALK突变热点区域第20~26号外显子的突变情况。结果：22 例儿童NB中,有10例（46%）在ALK第21号外显子上存在已知同义突变C3375A（Gly1125Gly）,等位基因频率为27%;1例（5%）在ALK第23号外显子上发现一个新的同义突变C3586T（Leu1196Leu）。ALK突变C3375A的发生频率在NB患儿的年龄、性别、肿瘤分化程度和是否转移方面差异无统计学意义（P＞0.05）。在其他5个ALK外显子中未发现突变。结论：采用PCR-DNA测序技术发现了ALK一个新的同义突变C3586T,并证实了儿童ALK存在已知突变C3375A,其发生率不受NB患儿临床特征的影响。     

家族性高胆固醇血症一家系成员低密度脂蛋白受体基因复合杂合突变分析

目的 对1例临床确诊为纯合型家族性高胆固醇血症(FH)先证者及其3代家系成员进行基因检测和系谱分析,探讨该FH患儿发病的分子病理基础.方法 收集FH先证者家系3代共29例血标本及临床资料.对先证者进行心电图和超声检查.对其家系成员进行血脂测定,改良苯酚-氯仿法提取患儿及家系成员基因组DNA并鉴定,应用多聚酶链反应-单链构象多态性(PCR-SSCP)分析结合DNA直接测序方法 ,检测其低密度脂蛋白受体(LDLR)基因全部18个外显子和启动子及载脂蛋白B100(ApoB100)R3500Q位点,核苷酸序列分析结果 与GenBank比对寻找突变.结果 1.血管超声示先证者右锁骨下动脉起始,双侧颈总动脉分叉处中段内-中膜轻度增厚,右侧颈总动脉中段后壁多发小钙化斑,主动脉瓣轻度关闭不全;2.该家系排除ApoB100基因R3500Q突变;3.核苷酸序列分析证实先证者及其父亲、祖父和叔叔等6人LDLR基因第10外显子发生W462X杂合突变,为色氨酸改变为终止密码子,使终止密码子在第462位提前出现;先证者及母亲和外祖母LDLR基因第13外显子发生A606T杂合突变,为第1 879位G→A碱基置换,导致丙氨酸改变为苏氨酸.结论 该FH先证者LDLR基因存在W462X/A606T复合杂合突变,分别来源于父系及母系遗传.这种复合杂合突变患者具有与FH纯合子相同的临床特征.     

儿童肾母细胞瘤WT1基因突变四例报道

目的 研究儿童肾母细胞瘤患者WT1基因的突变类型及突变频率.方法应用聚合酶链反应(PCR)扩增出54例儿童肾母细胞瘤患者WT1基因全部10个外显子及其相邻内含子序列,经纯化后进行PCR产物直接测序.结果 4例患者WT1基因分别存在3个杂合无义突变及1个纯合错义突变.例1患者WT1基因7号外显子第1006位碱基A→T杂合突变,造成第336号氨基酸由赖氨酸转变为终止密码子,即K336X.例2患者WT1基因9号外显子第1168位碱基c→T杂合突变,造成第390号氨基酸由精氨酸转变为终止密码子,即R390X.例3患者WT1基因6号外显子第814位碱基G→T杂合突变,造成第272号氨基酸由谷氨酸转变为终止密码子,即E272X.例4患者WT1基因10号外显子第1228位碱基A→G纯合突变,造成第410号氨基酸由丝氨酸转变为甘氨酸,即S410G.结论 散发的中国儿童肾母细胞瘤患者WT1基因外显子突变的发生率与国外报道相近,检测到的4例突变患者中3例为无义突变、1例为错义突变.     

先天性无肛畸形HoXA-1 3基因的改变

目的 检测先天性无肛畸形患儿基因组HoxA-13基因的改变。方法 应用聚合酶链反应-单链构象多态（PCR-SSCP）初步检测90例先天性无肛畸形患儿基因组HoxA-13基因第二外显子保守区的碱基改变,50例正常患儿作PCR-SSCP对照;阳性改变患儿PCR产物经DNA测序确定基因突变。结果 经PCR-SSCP及DNA序列分析确定2例高位畸形患者,HoxA-13基因第二外显子第158bp发生了点突变（T→G）,因为相对应的氨基酸也发生了改变（异亮氨酸→丝氨酸）,因而是有了点突变。结论 某些先天性肛门直肠畸形患儿HoxA-13基因保守区发生点突变,HoxA-13基因可能是先天性肛门直肠畸形的易感基因之一。     

Two novel mutations in the human thyroid peroxidase (TPO) gene: genetics and clinical findings in four children

We report four children originating from two unrelated German families with congenital hypothyroidism (CH) due to mutations in the thyroid peroxidase (TPO) gene. Three female siblings (family 1) were found to be compound heterozygous for two mutations, a known mutation in exon 9 (W527C), and a mutation in exon 8 (Q446H), which has not been described before. In the second family we identified a boy with goitrous CH, who had a novel homozygous mutation in the TPO gene in exon 16 (W873X). All children of family 1 were diagnosed postnatally by newborn screening. The case of the boy of family 2 has already been reported for the in utero treatment of a goiter with hypothyroidism.
Conclusion: Our results confirm existing data on the phenotypic variability of patients with TPO gene mutations.     

先天性甲状腺功能减退症患儿DUOX2基因突变的研究

目的 研究先天性甲状腺功能减退症(congenital hypothyroidism, CH)患儿DUOX2 基因突变类型和特点,并初步探讨基因型- 表现型的关系,为CH 患儿的基因诊断和基因治疗提供理论依据.方法 从10例CH 伴甲状腺肿大患儿外周血白细胞中提取基因组DNA,采用PCR 扩增和直接测序的方法对DUOX2 全部外显子进行基因突变检测.结果 在1 例患儿中发现DUOX2 基因第28 外显子cDNA 的3632 位点发生了G>A 的突变(c.G3632A),导致第1 211 密码子的精氨酸变为组氨酸(p.R1211H).在3 例患儿中发现DUOX2 基因第17 外显子cDNA 的2 033 位点发生了T>C 的突变(c.T2033C),导致第678 密码子的组氨酸变为精氨酸(p.H678R).此两种突变均为杂合型的错义突变.结论 CH 患儿存在DUOX2 基因杂合突变,该杂合突变可能引起蛋白质功能的改变从而导致CH;基因型与表现型的关系尚不明确,需要进一步的研究.     

TSHR is the main causative locus in autosomal recessively inherited thyroid dysgenesis

Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and results in mental retardation if untreated. Eighty-five percent of CH cases are due to disruptions in thyroid organogenesis and are mostly sporadic, but about 2% of thyroid dysgenesis is familial, indicating the involvement of genetic factors in the aetiology of the disease. In this study, we aimed to investigate the Mendelian (single-gene) causes of non-syndromic and non-goitrous congenital hypothyroidism (CHNG) in consanguineous or multi-case families. Here we report the results of the second part (n=105) of our large cohort (n=244), representing the largest such cohort in the literature, and interpret the overall results of the whole cohort. Additionally, 50 sporadic cases with thyroid dysgenesis and 400 unaffected control subjects were included in the study. In familial cases, first, we performed potential linkage analysis of four known genes causing CHNG (TSHR, PAX8, TSHB, and NKX2-5) using microsatellite markers and then examined the presence of mutations in these genes by direct sequencing. In addition, in silico analyses of the predicted structural effects of TSHR mutations were performed and related to the mutation specific disease phenotype. We detected eight new TSHR mutations and a PAX8 mutation but no mutations in TSHB and NKX2-5. None of the biallelic TSHR mutations detected in familial cases were present in the cohort of 50 sporadic cases. Genotype/phenotype relationships were established between TSHR mutations and resulting clinical presentations. Here we conclude that TSHR mutations are the main detectable cause of autosomal recessively inherited thyroid dysgenesis. We also outline a new genetic testing strategy for the investigation of suspected autosomal recessive non-goitrous CH.     

先天性原发性甲状腺功能减低症50例TSHR基因研究

目的探讨促甲状腺激素受体（TSHR）基因在先天性原发性甲状腺功能减低症（甲低）病因学中的地位。方法对50例先天性甲状腺功能减低症患者,从外周血白细胞中提取基因组DNA,采用PCR-SSCP方法对TSHR基因外显子10、6、1进行分析。结果在TSHR基因外显子10、6、1中未发现突变。结论已发现的TSHR基因编码区的结构改变,在中国人甲低的病因学中可能不具有重要地位。     

先天性甲状腺功能减退症患儿GNAS和THRA基因突变分析

目的 对70例先天性甲状腺功能减退症（CH）患儿的刺激性G蛋白α亚基（GNAS）基因和甲状腺素受体α（THRA）基因进行二代测序分析,并初步探讨GNAS和THRA基因突变型与CH患儿的临床表现型之间的关系。方法 选取70例通过新生儿筛查确诊为CH的患儿,采集外周血并进行DNA样本提取,利用二代测序技术对GNAS和THRA基因进行突变筛查,利用生物信息学软件分析基因突变的致病性。结果 70例CH患儿中,3例患儿（4%）检出9种GNAS基因的错义突变（包括3种已知基因突变和6种新突变）,4例患儿检出同1种THRA基因多态c.508A > G（p.I170V）。经过生物信息学软件预测和ACMG/AMP指南分析发现2种GNAS基因突变[c.301C > T（p.R101C）、c.334G > A（p.E112K）]致病的可能性大。3例携带GNAS基因突变的患儿存在不同程度的甲状腺功能低下表现。结论 GNAS基因突变与CH的发病有关,患儿的临床表现存在较大的异质性;THRA基因突变可能与CH的发病无相关性。     

LUTEINIZING HORMONE RECEPTOR MUTATIONS IN DISORDERS OF SEXUAL DEVELOPMENT AND CANCER

Human male sexual development is regulated by chorionic gonadotropin (CG) and luteinizing hormone (LH). Aberrant sexual development caused by both activating and inactivating mutations of the human luteinizing hormone receptor (LHR) have been described. All known activating mutations of the LHR are missense mutations caused by single base substitution. The most common activating mutation is the replacement of Asp-578 by Gly due to the substitution of A by G at nucleotide position 1733. All activating mutations are present in exon 11 which encodes the transmembrane domain of the receptor. Constitutive activity of the LHR causes LH releasing hormone-independent precocious puberty in boys and the autosomal dominant disorder familial male-limited precocious puberty (FMPP). Both germline and somatic activating mutations of the LHR have been found in patients with testicular tumors. Activating mutations have no effect on females. The molecular genetics of the inactivating mutations of the LHR are more variable and include single base substitution, partial gene deletion, and insertion. These mutations are not localized and are present in both the extracellular and transmembrane domain of the receptor. Inactivation of the LHR gives rise to the autosomal recessive disorder Leydig cell hypoplasia (LCH) and male hypogonadism or male pseudohermaphroditism. Severity of the clinical phenotype in LCH patients correlates with the amount of residual activity of the mutated receptor. Females are less affected by inactivating mutation of the LHR. Symptoms caused by homozygous inactivating mutation of the LHR include polycystic ovaries and primary amenorrhea.     

先天性巨结肠症SIP1基因外显子3和外显子4的突变分析

目的 探讨SIP1基因外显子3和外显子4与散发性先天性巨结肠(Hirschsprung disease,HD)的关联性.方法 检测150例HD患儿SIP1基因突变.采用PCR-变性梯度凝胶电泳(PCR-degenerating gel gradient electrophoresis,PCR-DGGE)与DNA测序法检测患儿SIP1基因exon3 and exon4的突变.另选取150例正常人(排除家族性顽同便秘及其他先天性消化道畸形史健康儿童)外周血DNA作为对照组.结果 在HD组exon3 PCR-DGGE发现83例异常电泳条带,测序证实67/83例SIP1发生在突变集中区域,为错义突变(ACC→ATC,苏氨酸→异亮氨酸).在HD组exon4发现101例异常电泳条带,测序证实68/101例SIP1发生在突变集中区域,有4种突变(CAC→TAC,组氨酸→酪氨酸;GAG→GAT,谷氨酸→天门冬氨酸;GCC→GTC,丙氨酸→缬氨酸;TGT→TTT,胱氨酸→苯丙氨酸).DGGE检测正常对照组中未发现异常电泳条带,测序未发现突变.结论 SIP1基因为HD的致病基因,突变类型多样,已发现热点突变;提示SIP1基因与HD发病存在一定程度的关联.     

Congenital hypothyroidism caused by a novel homozygous mutation in the thyroglobulin gene

Congenital hypothyroidism (CH) due to thyroglobulin (TG) deficit is an autosomal recessive disease (OMIM #274700) characterized by hypothyroidism, goiter, low serum TG, and a negative perchlorate discharge test. The aim of this study was to perform the genetic analysis of the TG gene in two sisters born from consanguineus parents and affected by CH and low serum TG levels. The index patient and her sister were identified at neonatal screening for CH and treated with L-thyroxine (L-T4). After discontinuation of L-T4 therapy, hypothyroidism was confirmed, serum TG was undetectable, and no organification defect after ¹²³I scintigraphy and perchlorate test was shown; thyroid ultrasound showed a eutopic gland of normal size. DNA was extracted from peripheral white blood cells of the two sisters and the father. All 48 exons of TG gene were amplified by polymerase chain reaction and subjected to direct sequencing. A novel homozygous point mutation in exon 10 of TG gene was identified in the patient and her sister. The mutation determined a stop codon at position 768 (R768X) resulting in an early truncated protein or in the complete absence of the protein. The father (euthyroid) was heterozygous carrier of the mutation. Conclusion: Genetic analysis of TG gene was performed in two sisters affected by CH. A novel point mutation of the TG gene determining a stop codon at position 768 of the protein was identified. The early truncated nonfunctioning protein or the absence of the protein due to the premature degradation of abnormal mRNA may be responsible of the observed phenotype.     

Novel TSHbeta subunit gene mutation causing congenital central hypothyroidism in a newborn male

Newborn screening programs that use only high TSH levels as a marker for hypothyroidism may overlook neonates with congenital hypothyroidism (CH) due to TSH deficiency. We sought the cause of TSH deficiency in a neonate with low levels of thyroxine and TSH. The coding region of the TSHbeta gene was amplified and its sequence examined for mutations. Two mutations in exon 3 were identified: 1) a nucleotide deletion of T410 in codon 105 resulting in a frameshift in one allele, and 2) a previously unreported nucleotide deletion of T266 in codon 57, causing a frameshift and a premature stop at codon 62 in the other allele. We describe a compound heterozygous patient with TSHbeta mutations at codons 57 and 105 that interfered with a critical disulfide bond in the TSH molecule and caused CH. State screening programs that measure both T4 and TSH levels have the potential to detect newborns with congenital central hypothyroidism.     

Genetic Analysis in Children with Transient Thyroid Dysfunction or Subclinical Hypothyroidism Detected on Neonatal Screening

About 30% of children with elevated TSH levels during neonatal screening have a transient form of disorder. On the other hand, it has been reported that subclinical hypothyroidism persists in late childhood in about 30% of children found to be false-positive during neonatal screening. The aim of this study was to determine whether transient thyroid dysfunction and subclinical hypothyroidism detected during neonatal screening are influenced by genetic background. The TSH receptor (TSHR), thyroid peroxidase (TPO) and dual oxidase 2 (DUOX2) genes, for which it has been reported that heterozygous defects cause neonatal transient thyroid dysfunction, were analyzed. Nine children with transient thyroid dysfunction or subclinical hypothyroidism detected during neonatal screening were studied. One child was heterozygous for a TSHR gene mutation (R450H), and another child was heterozygous for a TPO gene mutation (P883S). No children with mutation of the DUOX2 gene were identified. Genetic background may contribute to development of transient thyroid dysfunction and subclinical hypothyroidism detected during neonatal screening.