儿童1型原发性高草酸尿症七例临床分析

目的探讨1型原发性高草酸尿症(PH1)患儿的临床、影像、分子生物学特征,及临床表型与基因型的相关性.方法回顾性分析2016年6月至2019年5月广州市妇女儿童医疗中心肾内科住院经基因检测确诊为PH1的7例患儿(男4例、女3例)病例资料,分子生物遗传学检测方法采用对先证者进行肾小管疾病相关靶向基因外显子测序并采用Sanger测序法对家系进行验证,采用非条件Logistic回归分析统计肾钙质沉着与肾功能的关系.结果共纳入来自6个家庭的7例患儿,发病中位年龄5月龄,确诊中位年龄8月龄,5例已进展至终末期肾病、1例为慢性肾脏病2期、1例为慢性肾脏病1期.死亡4例、维持性透析1例、非透析随访患儿2例.婴儿型PH1患儿4例,儿童及青少年型1例,家族型1例,分类不明1例.2例为胞生姐弟,其中弟弟为先证者,因尿毒症而被确诊,姐姐继而因家系验证被确诊,为轻度肾功能不全,两人均有延迟诊断,弟弟延迟5年、姐姐延迟3年.7例患儿均有不同程度的尿蛋白升高(随机尿蛋白与尿肌酐比值的平均值为1.1)及镜下血尿、无肉眼血尿,3例患儿出现高钙尿症.综合CT、磁共振成像、X线片及超声等多种影像学检查,确诊4例单纯肾钙质沉着症、1例肾钙质沉着症伴肾石症、1例单纯多发肾结石及1例肾髓质小结晶,但其中超声检查能明确肾钙质沉着症的只有1例,其余4例由CT等放射性影像检查确诊,而且肾钙质沉着是肾功能不全的独立危险因素(OR 2.5,95%CI 0.7~1.2,P<0.05).基因检测7例均为AGXT基因变异,其中纯合变异4例、复合杂合变异3例.共发现9个变异基因型,有4个基因型出现在6号外显子变异,其中c.679_680del缺失变异3例(2例为胞生姐弟),c.679_680+2del缺失1例.结论PH1患儿以婴儿型为多见,病情进展迅速甚至以肾功能不全起病预后极差,是临床表型与基因型高度异质性疾病;肾钙质沉着是导致肾功能衰竭的一个独立危险因素,放射性影像检查对于肾钙质沉着症的诊断具有较高特异性;国内儿科领域PH1的漏诊及延迟诊断仍较突出,普遍开展尿草酸定量测定对降低漏诊率及追踪评估疗效具有重要意义.     

儿童原发性Ⅰ型高草酸尿症2例报告及文献复习

目的探讨原发性Ⅰ型高草酸尿症(PH Ⅰ)的临床特点、诊断及治疗。方法回顾分析2例PH Ⅰ患儿的临床表现、实验室检查结果,并对家系成员进行全外显子测序。结果 2例患儿发病年龄分别为2个月和1岁5个月,均有肾衰竭,伴不同程度贫血、肾石症等。全外显子测序发现2例患儿分别为AGXT基因c.815_816GA纯合变异及c.25_26 insC、c.815_816 insGA复合杂合变异。确诊为PH Ⅰ后给予肾脏替代联合对症治疗。结论 PH Ⅰ无特异性临床表现,部分患儿肾衰竭进展迅速。     

儿童原发性1型高草酸尿症临床及AGXT基因突变分析

目的探讨儿童原发性1型高草酸尿症(PH1)的临床及基因变异特点。方法回顾分析5例确诊PH1型患儿的临床资料。结果 5例患儿,男3例、女2例,发病年龄2个月～4岁;均有顽固性代谢性酸中毒、高钾血症、低钙血症等非特异性临床表现,年长患儿有多发性肾结石的特异性表现。基因检测显示,5例患儿均有AGXT基因不同位点的变异,共发现6个突变位点,3例患儿有6号外显子c.679_680del缺失突变,其中2号外显子c.190AT突变为首次报道。结论 PH1患儿临床表现多样,基因检测有助于早诊断、早干预,可延缓终末肾的进展。     

CLDN16 基因突变致家族性低镁血症高钙尿症与肾钙质沉着症1 例报告并文献复习

目的探讨家族性低镁血症高钙尿症和肾钙质沉着症(FHHNC)的临床特征和致病基因特点。方法分析1例2月龄FHHNC女性患儿的临床资料。结果患儿血镁低,尿钙高;肾脏超声提示肾髓质回声增强;多次尿培养大肠埃希菌。基因测序显示患儿CLDN16基因2处杂合变异c.324+1GC,c.317CT(p.Ser 106 Phe)。予抗感染及25%硫酸镁、门冬氨酸钾镁、10%枸橼酸钠口服治疗,病情好转。结论 FHHNC罕见且预后差,目前除肾移植外无特殊治疗方法,基因检测有助于早期诊断。     

儿童原发性1型高草酸尿症1例并文献复习

目的 总结儿童原发性1型高草酸尿症 (PH 1)临床资料,提高对该病的认识。方法 采集1例PH 1患儿的临床特点、影像学表现,肾结石分析信息;进行家系调查;对该家系相关成员进行AGXT基因外显子及附近调控区域直接测序,分析突变位点;文献综述。结果 女童,3岁时起病,首发症状为肉眼血尿,继腰、背部疼痛,体外震波碎石、排石治疗后结石复发,7年内进展为终末期肾病。腹部B超、X线平片和CT均提示多发双肾脏和输尿管结石。肾结石成份为单水草酸钙。未发现患儿家族有相同疾病的患者。AGXT基因分析发现,患儿存在c.242C>A（p.Ser81X）和c.823_824dupAG（p.Ser275delinsArgAlafs）杂合突变,其父亲携带c.823_824dupAG杂合突变,其母亲携带c.242C>A杂合突变。患儿为AGXT基因复合杂合突变,其中c.242C>A无义突变为首次报道。结论 PH 1为罕见遗传性疾病。经影像学证实为多发和复发性双肾结石,排除其他原因所致,应该考虑原发性高草酸尿症,肾结石成份和AGXT基因分析是PH 1诊断的重要手段,尤其AGXT基因分析在某些情况下可以替代肝穿刺成为PH 1确诊的无创检查;PH 1早期诊断和干预将会延缓肾功能恶化,改善预后。     

戊二酸尿症Ⅰ型1例临床和基因突变分析

目的探讨戊二酸尿症Ⅰ型的基因突变特点。方法回顾分析1例戊二酸尿症Ⅰ型患儿的临床资料及基因检测结果。结果女性患儿,1岁11个月,主要表现为腹泻及抽搐。血戊二酰肉碱水平(0.78μmol/L)及尿戊二酸显著增高。二代测序发现GCDH基因两处变异,c.271+1GA(IVS4+1GA),为父源性剪切变异;c.938GA为母源性错义变异。两处变异的致病性均已有文献报道,但均是国内首次报道。结论扩充了国内戊二酸尿症Ⅰ型的基因突变谱。     

6月龄女婴尿量减少伴急性肾功能异常

患儿,女,6月龄,急性起病,因尿量减少、肾功能异常入院。辅助检查提示严重代谢性酸中毒,血肌酐和尿素氮明显增高。予限制液体、纠正酸中毒、连续床旁血液净化等治疗10 d,患儿仍持续无尿,放弃治疗后死亡。患儿姐姐于6月龄死于急性肾功能衰竭。患儿经基因检测证实为丙氨酸乙醛酸氨基转移酶(AGT)编码基因AGXT突变引起的原发性高草酸尿症1型(PH1),其父母为杂合突变携带者。PH1是一种临床罕见疾病,对于肾功能显著异常,或伴反复发作肾结石,以及有类似家族史的患者,应考虑到PH1的可能,AGXT基因分析是PH1诊断的重要手段。     

糖原贮积病Ⅱ型GAA基因变异特点及基因型与表型的关系

目的:探讨糖原贮积病Ⅱ型患者酸性α-葡萄糖苷酶(GAA)基因变异特点及基因型与表型的关系,并根据健康儿童GAA基因变异携带率推断理论发病率。方法:回顾性分析2010年1月至2020年5月广州市妇女儿童医疗中心确诊的18岁前起病的57例糖原贮积病Ⅱ型患者的临床资料及GAA基因分析结果,采用荧光底物法检测外周血淋巴细胞或干血斑中GAA活性,采用Sanger测序法进行GAA基因变异分析。以2395名健康儿童全外显子测序中GAA基因检测计算GAA基因变异携带率。组间率的比较采用χ2检验。结果:57例患儿中男26例,女31例。婴儿型患者28例,主要表现为进行性全身肌无力及心肌肥厚,发病年龄(2.5±1.4)月龄,确诊年龄(5.0±3.0)月龄,其中26例于1岁内死亡。晚发型患者23例,表现为肌无力、呼吸困难等,发病年龄(12.0±5.0)岁,确诊年龄(17.0±7.5)岁,7例诊断时已出现呼吸衰竭。非典型婴儿型6例,1岁左右发病,表现为肌无力伴肥厚性心肌病,诊断年龄为2.5~7.0岁。GAA基因分析显示,57例患者共检出47种变异,其中3种错义变异c.797C>T、c.1109G>A及c.1757C>T为可能致病新变异。c.1935C>A(25/114,21.9%)和c.2238G>C(15/114,13.2%)为较常见变异,57.1%(16/28)婴儿型患者检出c.1935C>A的纯合或复合杂合变异,65.2%(15/23)晚发型患者携带c.2238G>C。c.796C>T及c.1082C>T多见于非典型婴儿型。在28例婴儿型患者中,26例(92.9%)至少携带1个错义变异。健康儿童GAA基因致病变异携带率为24/2395,推测该病的理论发病率为1/40000。患者组GAA变异谱与健康儿童携带的GAA变异谱基本一致,假性缺陷变异c.1726G>A和c.2065G>A纯合子检出率在患者组分别为26.3%(15/57)和35.1%(20/57),在健康儿童组分别为1.7%(40/2395)和3.9%(94/2395),两组比较差异均有统计学意义(χ2=151.2、121.9,均P<0.01)。结论:糖原贮积病Ⅱ型临床表现呈连续的临床谱特征,少数患者为非典型婴儿型。常见的2种变异c.1935C>A和c.2238G>C分别与婴儿型及晚发型有关,c.796C>T及c.1082C>T多见于非典型婴儿型。绝大多数婴儿型患儿因携带1个错义变异推测为交叉反应性免疫物质阳性。糖原贮积病Ⅱ型理论发病率约1/40000。     

Autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations: a report of 8 cases and literature review北大核心CSCD

目的 总结SYNGAP1基因相关常染色体显性智力障碍5型患儿临床表型及遗传学特点。方法 回顾性分析中南大学湘雅医院儿科诊治的8例SYNGAP1基因相关智力障碍患儿的临床资料。结果 8例患儿的平均起病年龄为9月龄,均伴有中重度发育迟缓(语言落后为著),其中7例患儿伴癫痫发作。8例患儿中7例为新发杂合变异(3例移码变异、2例无义变异和2例错义变异),1例为6p21.3微缺失。目前已报道的中国SYNGAP1基因变异相关智力障碍患儿(包括该研究)有48例,其中40例伴癫痫发作,癫痫发作平均起病年龄为31.4月龄,多为移码变异(15/48,31%)和无义变异(19/48,40%)。治疗上,有癫痫用药史记录的33例患儿中,丙戊酸抗癫痫发作治疗对多数患儿有效(85%,28/33),其中48%(16/33)患儿丙戊酸单药或联合用药治疗达到发作完全控制。结论 SYNGAP1基因相关常染色体显性智力障碍5型患儿起病年龄早,多数患儿伴癫痫发作,以移码变异和无义变异为主,丙戊酸抗癫痫发作治疗对多数患儿有效。     

IQSEC2基因变异相关癫痫基因型与临床表型特点

目的分析IQSEC2基因变异相关癫痫患儿的基因型与临床表型特点。方法收集2019年7月至2021年10月在北京大学第一医院儿科就诊的6例IQSEC2基因变异癫痫患儿的临床资料, 对其基因型特点和癫痫发作表现、脑电图、头颅影像学等结果进行回顾性分析。结果 6例患儿中男5例、女1例。6例IQSEC2基因变异均为新生变异, 其中移码变异2例(c.3801₃808dup/p.Q1270Rfs*130、c.1459₁460delAT/p.M487Vfs*2), 无义变异2例(c.3163C>T/p.R1055*、c.1417G>T/p.E473*), 框内缺失变异1例(c.2295₂297del/p.N765del)、错义变异1例(c.2293A>G/p.N765D)。癫痫起病年龄为3月龄至2岁5月龄。癫痫发作类型多样, 包括癫痫性痉挛、局灶性发作各5例, 强直发作、肌阵挛发作各3例, 不典型失神发作、失张力发作各2例。6例患儿癫痫起病前均有全面发育迟缓, 其他临床表现有孤独症样表现3例, 小头畸形3例, 肌张力...     

Primary hyperoxaluria type 2

Primary hyperoxaluria type 2 (PH2) is a rare disease with only 24 patients reported in the literature so far. It should be considered in any patient presenting with urolithiasis or nephrocalcinosis due to hyperoxaluria. The metabolic defect is deficiency of d-glycerate dehydrogenase/glyoxylate reductase leading to characteristic hyperoxaluria and excretion of l-glycerate, the cornerstone of diagnosis of PH 2. Although development of terminal renal failure seems to be less prevalent than in PH 1, recent reports indicate that chronic as well as terminal renal insufficiency may occur. Therefore specific therapeutic measures should aim at reduction of urinary calcium oxalate saturation by potassium citrate or pyrophosphate to reduce the incidence of nephrolithiasis and nephrocalcinosis and thus improve renal survival. Secondary complications (obstruction, urinary tract infections and pyelonephritis) must be avoided. In patients with terminal renal failure isolated renal transplantation seems to carry a high risk of disease recurrence. Conclusion PH 2 is a rare but important cause of urolithiasis and nephrocalcinosis; long-term follow up is necessary, since the renal prognosis may be worse than previously anticipated. Received: 22 November 1996 / Accepted: 17 January 1997     

Urinary oxalate excretion in urolithiasis and nephrocalcinosis.

AIMS: To investigate urinary oxalate excretion in children with urolithiasis and/or nephrocalcinosis and to classify hyperoxaluria (HyOx). METHODS: A total of 106 patients were screened. In those in whom the oxalate: creatinine ratio was increased, 24 hour urinary oxalate excretion was measured. Liver biopsy and/or genomic analysis was performed if primary hyperoxaluria (PH) was suspected. Stool specimens were examined for Oxalobacter formigenes in HyOx not related to PH type 1 or 2 (PH1, PH2) and in controls. RESULTS: A total of 21 patients screened had HyOx (>0.5 mmol/24 h per 1.73 m(2)); they were classified into five groups. Eleven had PH (PH1 in nine and neither PH1 nor PH2 in two). Six had secondary HyOx: two enteric and four dietary. Four could not be classified. Seven patients had concomitant hypercalciuria. Only one of 12 patients was colonised with O formigenes compared to six of 13 controls. CONCLUSIONS: HyOx is an important risk factor for urolithiasis and nephrocalcinosis in children, and can coexist with hypercalciuria. A novel type of PH is proposed. Absence of O formigenes may contribute to HyOx not related to PH1.     

Predisposing Factors for Nephrolithiasis and Nephrocalcinosis in Cystic Fibrosis

Objective

Cystic fibrosis (CF) is characterized by chronic pulmonary disease, insufficient pancreatic and digestive function, and abnormal sweat concentration. There is controversy about predisposing factors of nephrolithiasis and nephrocalcinosis in patients with cystic fibrosis. We assessed the results of metabolic evaluation in patients with cystic fibrosis and its correlation with nephrocalcinosis.

Methods

Forty five CF patients, mean age 47.1 months, were enrolled in the study. No one had past history of nephrolithiasis and/or nephrocalcinosis. The records were reviewed for clinical characteristics and all patients underwent metabolic evaluation including serum electrolyte measurements and spot urine analysis. Ultrasonography was performed in all patients to detect nephrocalcinosis and urolithiasis.

Findings

Nephrocalcinosis was found in 5 (11%) patients. No patient had clinical symptoms of nephrolithiasis and/or micro/macroscopic hematuria. Metabolic evaluation of the CF patients versus normal reference values showed decreased serum uric acid in 48.8%, elevated serum phosphate in 24.4%, and urine oxalate excretion in 51%. Metabolic evaluation of the nephrocalcinosis positive patients versus nephrocalcinosis negative group showed no statistical difference in serum electrolytes. The mean value of urine calcium excretion was lower in patients with nephrocalcinosis (P=0.001). Despite lack of any significant correlation, higher numerical hyperoxaluria was observed in patients with severe steatorrhea. There was no statistical correlation between steatorrhea and urine calcium as well as oxalate excretion.

Conclusion

Hypocalciuria in the nephrocalcinotic CF patients may be seen. It can be hypothesized that hypocalciuria may be due to a primary defect in renal calcium metabolism in CF patients.     

Systemic oxalosis: Pathognomonic renal and specific extrarenal findings on US and CT

Hyperoxaluria is characterized by nephrocalcinosis and nephrolithiasis on radiological examination and may also result in diffuse deposition of calcium oxalate crystals in multiple extrarenal organs (oxalosis). In two cases, the renal findings of primary hyperoxaluria were diagnosed by ultrasound and computed tomography scans. In addition to renal involvement, both patients had liver involvement, and one patient had cardiac involvement.     

Long-term results of pre-emptive liver transplantation in primary hyperoxaluria type 1

In primary hyperoxaluria type 1 (PH 1), deficiency or mistargeting of hepatic alanine glyoxylate aminotransferase (AGT) results in over-production of oxalate and hyperoxaluria, leading to nephrocalcinosis and development of end-stage renal disease (ESRD) in the majority of patients. Renal transplantation (Tx) alone carries a high risk of disease recurrence as the metabolic defect is not cured. Therefore, combined liver/kidney Tx is recommended for patients with ESRD. An alternative approach is to cure PH 1 by pre-emptive isolated liver Tx (PLTx) before ESRD has occurred, but this approach has been carried out only occasionally and there are no uniformly accepted recommendations concerning the timing of this procedure. We report follow-up 3-5.7 yr after performing successful PLTx in four children (at the age of 3-9 yrs) with PH 1 prior to the occurrence of ESRD (glomerular filtration rate [GFR] range 27-98 mL/min/1.73 m2). There was no mortality or long-term morbidity associated with the Tx procedure. Plasma and urinary oxalate levels normalized rapidly within 4 weeks, and renal function did not deteriorate under immunosuppression, even in one patient with advanced chronic renal failure (GFR 27 mL/min/1.73 m2) who showed a stable course for more than 5.7 yrs. Although treatment must be individualized in this severe metabolic disorder, and PLTx has to be regarded as an invasive procedure, we consider that PLTx should be offered and considered early in the course of PH 1. PLTx cures the metabolic defect in PH 1 and can help to prevent, or at least delay, the progression to ESRD and systemic oxalosis.     

Renal calculi in children

An increasing number of paediatric patients of all ages with renal calculi are being seen in outpatient clinics worldwide. This is attributed to changes in environmental factors like diet, fluid intake and obesity. In children however, genetic and/or metabolic disorders are still the main reason for kidney stones. Next to hypercalciuria, which is generally considered to be the most frequent risk factor, other lithogenic or stone-inhibitory disorders like hypocitraturia or hyperoxaluria and a variety of renal tubular diseases have to be evaluated by urine and/or blood analysis. Non-specific symptoms like growth retardation, intestinal malabsorption or bone demineralization are to be considered not only to avoid further complications, but for diagnostic purposes. In preterm infants a high incidence of nephrocalcinosis is observed. These infants often have a combination of immature kidney function or medication that leads to relative hypocitraturia. Concise evaluation to diagnose the underlying patho-mechanism as early as possible is mandatory in all paediatric patients. In more than three-quarters of children a metabolic basis of urolithiasis/nephrocalcinosis will be found. Early treatment by reducing urinary saturation index by increasing fluid intake, by providing crystallization inhibitors, but also by disease specific medication prevents recurrent kidney stones and/or progressive nephrocalcinosis and therefore deterioration of renal function.     

Urinary oxalate excretion in urolithiasis and nephrocalcinosis

AIMS—To investigate urinary oxalate excretion in children with urolithiasis and/or nephrocalcinosis and to classify hyperoxaluria (HyOx).METHODS—A total of 106 patients were screened. In those in whom the oxalate: creatinine ratio was increased, 24 hour urinary oxalate excretion was measured. Liver biopsy and/or genomic analysis was performed if primary hyperoxaluria (PH) was suspected. Stool specimens were examined for Oxalobacter formigenes in HyOx not related to PH type 1 or 2 (PH1, PH2) and in controls.RESULTS—A total of 21 patients screened had HyOx (>0.5 mmol/24 h per 1.73 m²); they were classified into five groups. Eleven had PH (PH1 in nine and neither PH1 nor PH2 in two). Six had secondary HyOx: two enteric and four dietary. Four could not be classified. Seven patients had concomitant hypercalciuria. Only one of 12 patients was colonised with O formigenes compared to six of 13controls.CONCLUSIONS—HyOx is an important risk factor for urolithiasis and nephrocalcinosis in children, and can coexist with hypercalciuria. A novel type of PH is proposed. Absence of O formigenes may contribute to HyOx not related to PH1.     

Antibiotic treatment-induced tubular dysfunction as a risk factor for renal stone formation in cystic fibrosis

OBJECTIVES: Our purpose was to characterize the decisive pathophysiologic factors that lead to renal stone formation (nephrolithiasis) in patients with cystic fibrosis (CF). METHODS: Patients with CF (n = 96) were investigated with respect to lithogenic and inhibitory factors of urolithiasis and compared with 30 healthy control patients. They were subdivided into 2 groups, 86 without renal stones and 10 with renal stones. RESULTS: All stones were exclusively composed of calcium oxalate. As a major pathogenic factor, a urinary disequilibrium between promoting and inhibitory components of stone formation, characterized mainly by hypercalciuria, hyperoxaluria, and hypocitraturia, was found in the patients with nephrolithiasis. They tended to have lower plasma phosphate concentrations and an increased urinary phosphate excretion. The citrate/calcium ratio proved to be a valuable means to discriminate patients with renal stones from control patients. Patients with stones had ingested more cotrimoxazole and ceftazidim, cumulatively, than patients without stones. There was an inverse correlation between the amounts of antibiotics ingested and the percentage of tubular phosphate reabsorption (r = -0.91, P <.0046). CONCLUSION: Renal stone formation in patients with CF is caused by a disequilibrium between promoting and inhibitory components of stone formation, which is dominated by hypercalciuria, hyperoxaluria, and hypocitraturia. Treatment with cotrimoxazole and ceftazidim, primarily, may lead to renal proximal tubular damage with an ensuing sequence of phosphate loss, increase of parathyroid hormone secretion, increased 1,25-dihydroxyvitamin D3 formation, and absorptive hypercalciuria.     

Urinary citrate excretion in idiopathic nephrolithiasis

OBJECTIVE: To determine urinary citrate excretion in children with nephrolithiasis and normal controls. DESIGN: Prospective. SETTING: Tertiary care center in New Delhi. METHODS: This study was done on 50 children, below the age of 12 years, with idiopathic urinary calculi and 150 age and weight matched controls. The children were divided into 3 groups: Group 1 (1-4 years), Group 2 (5-8 years) and Group 3 (9-12 years). Urinary citrate was estimated in a 24-hour urine sample using colorimetric method. The stones removed from these children were also analysed. RESULTS: There was a preponderance of urinary stones in males; the highest incidence being in Group 1. Excretion of citrate in 24-hour urine sample was significantly lower in patients compared to controls, for males in all age groups and for females in Group 3. However, there was no statistically significant difference in the urinary citrate value between males and females in a given age group for either controls or patients. The urinary citrate excretion increased with age in patients and controls, but the levels in patients were lower. Depending upon the constituents, four types of stones were identified, calcium phosphate, calcium oxalate, uric acid and magnesium ammonium phosphate. Nine stones had at least more than one major constituent. Hypocitraturia was detected in 43 percent cases. The incidence was 76 percent for calcium phosphate, 87 percent for calcium oxalate, 40 percent for uric acid stones and 50 percent for magnesium ammonium phosphate. CONCLUSION: This study shows that low urinary citrate is associated with urinary stones in children, especially in endemic areas, in the absence of obvious etiological factors. Urinary citrate excretion should be determined in all children with nephrolithiasis.