低磷酸酶血症一家系组织非特异性碱性磷酸酶TNSALP基因突变分析

 目的 对1例儿童型低磷酸酶血症（HPP）患者及家系进行临床分析及基因突变检测,以探讨HPP的致病机制。方法 针对1例罕见的HPP患者的典型临床特点,进行实验室检验及影像学检查。进而收集患者及其亲属外周血,提取基因组DNA。针对ALPL基因12个外显子及附近内含子区合成引物,经PCR扩增后,直接对产物测序检测突变。结果 显示患者血碱性磷酸酶水平显著降低,骨骼具有佝偻病样改变;患者ALPL基因存在c.18delA及c.G407C两种突变。前者所致移码突变使得翻译提前终止,形成的截短蛋白 (p.V7Yfs18X)丧失了发挥酶活性及骨骼矿化作用的重要区域;而c.G407C导致其编码的氨基酸由精氨酸变为脯氨酸（R136P）。进一步检索PubMed及ALPL基因突变数据库,以上突变在国内外均未见报道。临床表现正常的患者母亲及祖母、父亲分别携带c.18delA和c.G407C突变,该家系符合常染色体隐性遗传。结论 ALPL基因c.18delA和c.G407C两种新突变,与HPP临床表现密切相关。     

婴儿型低磷酸酶血症组织非特异性碱性磷酸酶基因突变检测

目的 对1例婴儿型低磷酸酶血症患者及其父母进行临床分析和基因突变检测,以探讨该病的致病机制.方法 针对1例罕见的婴儿型低磷酸酶血症患者进行实验室检验及影像学检查.进而提取患儿及其亲属外周血基因组DNA,采用针对组织非特异性碱性磷酸酶ALPL基因调控区及编码区的特异性引物进行PCR扩增,直接对产物进行测序,并对所鉴定的突变在无关人群中进行验证.结果 患儿血碱性磷酸酶水平显著降低,同时存在高钙血症、中度贫血及双肾钙化;骨骼具有佝偻病样改变.ALPL基因测序结果显示患儿为复合杂合突变,同时携带位于第7外显子的c.814C ＞T (p.R272C)错义突变及位于第9外显子的c.1101_1103 delCTC (p.S368 del)碱基缺失突变.临床表现正常的患儿母亲、父亲为杂合子,分别携带c.1101_1103 delCTC (p.S368del)碱基缺失突变及c.814C ＞T (p.R272C)错义突变.该家系符合常染色体隐性遗传,50例无关健康个体验证未发现上述两种突变存在.结论 ALPL基因c.814C＞T(p.R272C)和c.1101_1103 delCTC(p.S368del)突变与该家系婴儿型低磷酸酶血症临床表现密切相关.     

一例骨骼发育异常胎儿ALPL基因的遗传学分析

低磷酸酯酶症(hypophosphatasia,HPP)是一种由于编码组织非特异性碱性磷酸酶(tissue non-specific alkaline phosphatase,TNSALP)的碱性磷酸酯酶基因(alkaline phosphatase gene,ALPL)变异导致的罕见常染色体显性或隐性遗传病,临床表现主要是骨骼和牙齿矿化不全以及血清碱性磷酸酶(ALP)活性偏低[1]。     

低磷酸酶血症的研究进展

低磷酸酶血症(HPP)是一种罕见的以骨和(或)牙齿矿化障碍,伴有血清碱性磷酸酶活性降低为特征的遗传性疾病.该病临床异质性强,容易造成漏诊和误诊.诊断主要依赖于临床表现、血清碱性磷酸酶降低及影像学特征.ALPL基因突变是诊断低磷酸酶血症必不可少的条件.HPP患者不建议使用维生素D和双膦酸盐.酶替代疗法将是未来几年最有前景的治疗方法.     

婴儿型低磷酸酶血症1例报告

<正>低磷酸酶血症(hypophosphatasia,HPP)由Rathbun在1948年首次提出^[1]。它主要是由组织非特异性碱性磷酸酶(tissue non-specific alkaline phosphatase,TNSALP)活性减低引起钙磷代谢异常,从而导致骨骼或牙齿矿化障碍的遗传代谢性疾病,也可出现癫痫、肌无力等症状。TNSALP由ALPL (the liver/bone/kidney alkaline phosphatase gene)基因编码,该基因的致病变异常导致TNSALP活性改变,     

Clinical, Pathological and Genetic Evaluations of Patients with Hypoplasia of Teeth Roots

Objective Hypoplasia of teeth root （HTR） is a genetic disease with defective teeth root. It is one of the most serious causes of teeth shedding earlier. Some inherited diseases could cause HTR phenotype. Methods We collected three HTR cases, and examined them carefully by clinical and laboratory test, especially their earlier shed teeth by histopathological methods. Based on clinical diagnoses and pathological manifestations, candidate genes ALPL and EDA were picked up to analyze and screen mutations. Results Three HTR patients showed distinct phenotypes, including systemic and dental abnormalities, whichrepresented many unique and hitherto undescribed disorders with concomitant HTR diseases. Then sequencing of ALPL and EDA indicated that three mutations of R136H and P446G in ALPL, L330P in EDA were separately found in three patients. Conclusion The mutations could increase the susceptibility to HTR disease or could be a causative factor. Our discoveries identified the potential functions of ALPL and EDA in teeth root initiation.     

Severe hypophosphatasia: characterization of fifteen novel mutations in the ALPL gene

Hypophosphatasia is an inherited disorder characterized by defective bone mineralization and deficiency of serum and tissue liver/bone/kidney alkaline phosphatase (L/B/K ALP) activity. We report the characterization of ALPL gene mutations in a series of 11 families from various origins affected by perinatal and infantile hypophosphatasia. Sixteen distinct mutations were found, fifteen of them not previously reported: M45V, G46R, 388-391delGTAA, 389delT, T131I, G145S, D172E, 662delG, G203A, R255L, 876-881delAGGGGA, 962delG, E294K, E435K, and A451T. This confirms that severe hypophosphatasia is due to a large spectrum of mutations in Caucasian populations.     

牙齿型低碱性磷酸酯酶症患儿ALPL基因的新突变

目的探讨牙齿型低碱性磷酸酯酶症的实质病因。方法本研究采用临床、实验室检查和遗传学方法对患儿进行临床病理诊断及致病候选基因筛选,并通过基因测序方法探寻突变位点。结果这例牙齿型低碱性磷酸酯酶症患儿的ALPL基因突变型为1581C>G,P446G。结论经数据库及文献检索这是一种新的基因突变型,该基因型是导致患儿疾病表型的影响因素。