Complex Heterozygous Mutation Research Articles

Clinical features, treatment, and follow-up of OPPG and high-bone-mass disorders: LRP5 is a key regulator of bone mass.

Low-density lipoprotein receptor-related protein 5 (LRP5) is involved in the canonical Wnt signaling pathway. The gain-of-function mutation leads to high bone mass (LRP5-HBM), while the loss-of-function mutation leads to osteoporosis-pseudoglioma syndrome (OPPG). In this study, the clinical manifestations, disease-causing mutations, treatment, and follow-up were summarized to improve the understanding of these two diseases. Two OPPG patients and four LRP5-HBM patients were included in this study. The clinical characteristics, biochemical and radiological examinations, pathogenic mutations, and structural analysis were summarized. Furthermore, several patients were followed up to observe the treatment effect and disease progress. Congenital blindness, persistent bone pain, low bone mineral density (BMD), and multiple brittle fractures were the main clinical manifestations of OPPG. Complex heterozygous mutations were detected in two OPPG patients. The c.1455G > T mutation in exon 7 was first reported. During the follow-up, BMD of two patients was significantly improved after bisphosphonate treatment. On the contrary, typical clinical features of LRP5-HBM included extremely high BMD without fractures, torus palatinus and normal vision. X-ray showed diffuse osteosclerosis. Two heterozygous missense mutations were detected in four patients. In addition, age-related bone loss was found in one LRP5-HBM patient after 12-year of follow-up. This study deepened the understanding of the clinical characteristics, treatment, and follow-up of OPPG and LRP5-HBM; expanded the pathogenic gene spectrum of OPPG; and confirmed that bisphosphonates were effective for OPPG. Additionally, it was found that Ala242Thr mutation could not protect LRP5-HBM patients from age-related bone loss. This phenomenon deserves further study.

Follow-up of infants with mild-to-moderate sensorineural hearing loss over three years.

To observe and analyse the hearing outcome in infants with mild-to-moderate sensorineural hearing loss (SNHL) who failed universal newborn hearing screening (UNHS). This retrospective cohort analysis included infants with mild-to-moderate SNHL and with complete etiological diagnosis and followed up over three years. Out of 96 infants with mild-to-moderate SNHL 72 were stable (75%). Only one case was normal (1.04%), ten cases were improved (10.42%), and 13 were deteriorated (13.54%). The pathogenic mutation of GJB2 was the most common cause (50/96, 52.08%), and most of them were homozygous or complex heterozygous mutations of p.V37I (44/50, 88%). There were 11 cases (11.49%) with large vestibular aqueduct syndrome (LVAS) and nine cases (9.38%) with perinatal risk factors. Infants with GJB2 pathogenic mutation and those without certain etiology mostly had unchanged hearing levels, accounting for 84% (42/50) and 84.61% (22/26), respectively. Hearing deterioration in LVAS was associated with seven cases (63.64%). There was no difference in types of outcomes in perinatal risk factor infants, who were more likely to improve than the other groups, but there were three cases (33.3%) deteriorated to profound hearing loss. Comparison of outcomes of different etiologies showed statistically significant difference (Chi-square=28.673, p=0.000). Normal and improved hearing in infants with mild-to-moderate SNHL was rare before the age of three, unlike in many previous studies, and appropriate intervention is recommended. However, intervention should be adjusted according to the hearing outcomes because of the possibility of improvement or deterioration. The etiological diagnosis of infants with mild-to-moderate SNHL would be helpful for predicting the outcome and managing intervention.

A novel PRKDC mutation caused B lymphocytes V(D)J rearrangement disorder in the SLE-DAH like symptoms patient

BackgroundAnalyzed the clinical features and treatment process of the patient suffering from immunodeficiency with systemic lupus erythematosus(SLE)-like syndrome in a novel mutation of PRKDC.Case presentationThe patient had multiple positive auto-antibodies, chest CT and bronchoscopy showed Diffuse alveolar hemorrhage(DAH), and psychiatric symptoms showed brain atrophy by magnetic resonance imaging (MRI). Whole exon sequencing showed that novel complex heterozygous mutations of PRKDC gene (C. 1777 − 710_1777-709INSA (IVS16/IC16), C.1337T > A(p.Phe446Tyr). The mature B cell (CD19 + CD27 + CD38 dimIgD IgM-) were absent. The treatment of high-dose methylprednisolone (MP) and cyclophosphamide(CTX) can quickly relieve the symptoms of the patient.ConclusionWe described the case of an infant immunodeficiency with SLE like-syndrome, which may cause by PRKDC mutation, treated successfully with high-dose MP and CTX.

Variability of clinical manifestations in the child with Roifman syndrome

Introduction. Roifman syndrome is a rare hereditary autosomal recessive disease, often associated with primary immunodeficiency and spondyloepiphyseal dysplasia. The cause of the disease is a splicing disorder due to a mutation of the RNU4ATAC gene with the formation of an incorrect protein structure, which in turn leads to clinical polymorphism.
 Purpose: demonstration of own clinical observation of the 5-year girl with Roifman syndrome.
 Materials and methods. An analysis of the literature on the stigmas of dysembriogenesis, clinical manifestations, changes in the immune system that determine the formation of Roifman syndrome was carried out.
 Results. The features of the course and variability of manifestations in the particular patient with Roifman syndrome are described. The variety and non-specificity of clinical symptoms in Roifman syndrome in the 5-year girl is shown. Timely diagnosis after complete sequencing by Sanger made it possible to identify a complex heterozygous mutation in the RNU4ATAC gene and start adequate therapy.

One case of congenital myopathy caused by new mutation of RYR1 gene and literature review

ObjectiveTo report a case of congenital myopathy caused by RYR1 gene complex heterozygous mutation and analyze the pathogenicity of the mutation. Method The clinical manifestation, laboratory examination, imaging findings, muscle pathology and gene test results of a child with congenital myopathy were analyzed retrospectively. Combined with literature review, it is analyzed and discussed. Result The child, female, was admitted to hospital because of “dyspnea for 22 min after asphyxia resuscitation”. The main manifestations are low muscle tension, the original reflex cannot be drawn out, the trunk and proximal muscles are weak, and the tendon reflex is not drawn out. The pathological signs were negative. The electrolyte of blood liver and kidney function, blood thyroid and blood ammonia were not abnormal, and creatine kinase increased temporarily. Electromyography suggests myogenic damage. Whole exome sequencing showed that there was a new compound heterozygous variation in RYR1 gene c.14427_ 14429del/c.14138C＞T.Western blot showed that the expression of RYR1 protein in patients was significantly lower than that in normal controls. Conclusion The compound heterozygous variation of RYR1 gene c.14427 was reported for the first time in China_ 14429del/c.14138c > t is the pathogenic gene of the child. The new discovery of RYR1 gene spectrum was revealed, which expanded the RYR1 gene spectrum.

Recurrent pancreatitis and sepsis in glycogen storage disease type Ia caused by complex heterozygous mutations in 2 sisters: Case report.

Glycogen storage disease (GSD) is a glycogen metabolism disorder caused by congenital enzyme defects, with type I being the most common. Owing to the rarity of glycogen storage disease type Ia (GSD Ia) and the involvement of diverse systems, patients are prone to delayed diagnosis and inappropriate treatment. Additional studies are required to standardize the diagnosis and treatment of GSD Ia. We report 2 cases of GSD Ia that occurred in 2 sisters. The elder sister also had recurrent pancreatitis, and the pancreatic pseudocyst rupture resulted in sepsis, portal hypertension, and splenic infarction. The younger sister had the same mutation site, but the clinical phenotypes were not identical. Abdominal computed tomography and laboratory examinations revealed regional portal hypertension, splenic infarction, and sepsis in the elder sister; diagnosis was confirmed by whole exome sequencing. Sanger sequencing was used to confirm that the younger sister and their parents also had the mutation site. The elder sister was treated with corn starch therapy, and medication for antiinfection and reducing hypertriglyceridemia, inhibiting trypsin activity, relieving hyperuricemia. The younger sister was treated with raw cornstarch-based nutritional therapy and sodium bicarbonate. The elder sister's infection was controlled and she gradually returned to a normal diet. After discharge, hyperlipidemia was not controlled satisfactorily, but hypoglycemia, hyperuricemia, hyperlactatemia, and anemia improved. GSD should be considered in childhood patients with hypoglycemia, hypertriglyceridemia, hyperuricemia, and hyperlactatemia. Gene sequencing can enable quick identification of GSD subtypes. This case report highlights the common clinical manifestations can be linked to rare diseases. Clinical work requires careful observation of the correlations between patient history, physical examinations, and laboratory examinations.

Generation of human induced pluripotential stem cells from individuals with complex heterozygous, isogenic corrected, and homozygous Bloc1s1 mutations

Genetic studies show that BLOC1S1 modulates mitochondrial and endosome-lysosome function (Wu et al., 2021a). Furthermore, Bloc1s1 mutations are linked to leukodystrophy (Bertoli-Avella et al., 2021). The Vanderver laboratory identified additional individuals with leukodystrophy that harbored either complex heterozygous (Bloc1s1 c.206A > C and c.359G > A), or homozygous (Bloc1s1 c.185 T > C) point mutations. We generated induced pluripotential stem cell (iPSC) lines from these subjects, from parents of the complex heterozygous mutations patient, and from CRISPR isogenic (c.206A > C and c.359G > A) corrected iPSC-line. These complex heterozygous, homozygous, and isogenic-corrected Bloc1s1 lines were phenotypically normal and were capable of differentiation towards the three germ layers.

Clinical characteristics and CYP17A1 gene mutation analysis in patients with 17α-hydroxylase/17, 20-lyase deficiency and testicular tumor

The 17α-hydroxylase/17, 20-lyase deficiency (17-OHD) is a rare disease. The clinical characteristics and gene mutation of 2 late-diagnosed 17-OHD patients with testicular tumor admitted to our hospital from March 2018 to February 2019 were analyzed retrospectively. The two 17-OHD patients were female (46, XY). Laparoscopic abdominal exploration found undeveloped testicles in grey-yellow or grey-red in the groin and iliac fossa. The testicles were removed and showed malignancy in pathology study. Sequencing of the CYP17A1 gene identified c.1247G>A/c.1427T>C and c.985_987delTACinsAA/c.1306G>A complex heterozygous mutations. Taking together, the possibility of 17-OHD should be considered in patients with hypertension, hypokalemia, adrenal adenomatoid hyperplasia together with 46, XY gonadal dysplasia, so as to make early diagnosis and treatment, and avoid dysplastic testicular turning to malignancy.

Genetic analysis of a family with metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is a rare autosomal recessive lysosomal storage disease caused by a deficiency of the enzyme arylsulfatase A (ARSA), which is encoded by the ARSA gene. Mutations discovered in the ARSA gene continuously improve our knowledge and understanding of this rare disease. We identified a Chinese family with 15 members. Two of them were diagnosed as MLD. We used Sanger sequencing to analyze eight exons of the ARSA gene and measured the ARSA activity in leukocyte or amniotic cells with p-nitrocatechol sulfate as the substrate. The potential pathological functions of these variants were predicted through SIFT, Polyphen2, and Mutation Taster. Two family members with a diagnosis of MLD were a two-year-old boy and a fetus. Both had a complex heterozygous mutation: c.413C > T (p.Pro138Leu) in exon 2 and c.1344dupC (p.G449fs) in exon 8. This complex heterozygous mutation is the first case of concurrent missense and code shift mutations reported in MLD in China. In these two family members, ARSA activity (20 nmol/17 h/mg protein and 9.8 nmol/17 h/mg protein) is only 10% compared to the normal population.

Three cases of 3β-hydroxysteroid dehydrogenase deficiency: Clinical analysis.

3β-HSD deficiency is a rare type of congenital adrenal hyperplasia (CAH), which is caused by HSD3B2 gene mutations. In order to improve the understanding and diagnosis of the disease, we analyzed and summarized the clinical characteristics, genetic variants and treatment for 3 children with 3β-HSD deficiency in this study. A summary of the clinical data, hormone levels (17-hydroxyprogesterone, adrenocorticotropic hormone, cortisol, testosterone, dehydroepiandrosterone, androstenedione, renin, and aldosterone), therapeutic drugs, and gene sequencing results from 3 3β-HSD deficiency patients was created. The 3 patients developed external genital abnormalities and adrenal insufficiency in infancy. Steroid hormone levels were consistent with 3β-hydroxysteroid dehydrogenase deficiency. Gene sequencing for the 3 patients detected complex heterozygous mutations in the HSD3B2 gene, which confirmed the diagnosis of 3β-HSD deficiency type II. Among the mutation types, c.154_162delinsTCCTGTT and c.674T>A have not been reported in the literature. The 3 children were treated with glucocorticoid and mineralocorticoid replacement, which controlled the adrenal insufficiency satisfactorily. In 2 male patients, external genital dysplasia manifested as hypospadias and small penis. After long-acting testosterone intramuscular injection to increase the penis size, the hypospadias were repaired. Mild masculinization in the female patient resulted in skin pigmentation and clitoral hypertrophy; however, no surgical intervention was required. The main clinical manifestations of 3β-HSD deficiency were adrenal insufficiency and sex hormone synthesis dysfunction. There was a strong phenotype correlation between the observed clinical manifestations in conjunction with steroid hormone levels and HSD3B2 mutations. The novel mutations c.154_162delinsTCCTGTT and c.674T>A were classified as pathogenic variants. Adrenal cortical function control was satisfactory after hormone replacement therapy, and hypospadias and small penis were attenuated using testosterone replacement therapy during mini-puberty for optimal surgical outcome.

Nonsyndromic deafness due to compound heterozygous mutation of the CDH23 gene

Objective:To identify the pathogenic gene mutation of two patients with non-syndromic deafness（NSHL）. Methods:Two patient with NSHL and their parents were selected in the research object. Each participant provided 3-5 mL of peripheral venous blood, which was used to establish a DNA library. Next generation sequencing was used to detect the sequence of the patient's genome, and the sequencing results were compared with the human genome sequence （GRCh）37/hg19. Sanger sequencing was used to verify the parents' genome sequence. Finally the patient's pathogenic gene mutation was confirmed.Amino acid conservatism and single nucleotide polymorphisms of the mutant sites were analyzed using a variety of databases and software. Results:The mutation was located to CDH23 gene in the chromosomal location 10q21-q22. Complex heterozygous mutations consist of c. 1343T>C and c. 7991_7993delTCA. Parents are heterozygous carriers of a single mutation. Conclusion:The next generation sequencing technology were used to screen the pathogenic gene mutation of inherited deafness. Combined with the genetic sequencing results of parents, the specific pathogenic gene mutation of deafness patients can be identified. While the pathogenicity of complex heterozygous mutation were explained by various pathogenicity analysis methods.

A novel compound heterozygous mutation in MYSM1 gene in a 1-month-old girl: a bone marrow failure syndrome 4 family survey and literature review

目的报道1例MYSM1基因复合杂合变异致骨髓衰竭综合征4型患儿临床表现及全外显子检测结果，同时报道其家系全外显子检测结果，为早期诊断此类骨髓衰竭综合征提供典型案例。方法报道1例1月龄骨髓衰竭综合征4型患儿临床诊断过程，并对患儿及其家系成员外周血DNA进行全外显子测序，使用BWA、GATK等软件对测序结果进行注释分析。结果本例1月龄骨髓衰竭综合征4型患儿，表现为全血细胞减少、多指畸形，影像学示非特异性脑白质改变及囊肿，淋巴细胞亚群分类示CD3−CD19+ B细胞降低。通过家系全外显子测序检测，鉴定患儿携带分别遗传自父母的MYSM1基因复合杂合性变异NM_001085487.2:c.1607_c.1611delAAGAG和c.1432C>T。家系验证证实先证者父亲携带的c.1432C>T突变来源于先证者祖父，先证者母亲携带的c.1607_c.1611delAAGAG突变来自于先证者外祖父，其他家系成员均不携带突变。结论本研究新发现MYSM1致病性变异c.1607_c.1611delAAGAG，国内外尚未见报道。本例为BMFS4的早期诊断提供了典型案例，并扩展了MYSM1基因致病性变异谱和表型谱。

Analysis of Phenotype and Genotype of A Family with Hereditary Coagulation Factor Ⅴ Deficiency Caused by A Compound Heterozygous Mutation

To analyze the molecular pathogenesis by analysis of phenotype and gene mutation in families with hereditary coagulation factor V (FⅤ) defect caused by complex heterozygous mutation. Plasma pro-thrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), FⅤ procoagulant activity (FⅤ∶C), FⅤ antigen (FⅤ∶Ag), and other related coagulation indexes were detected in the proband and his family members (3 generations 10 people). Using DNA direct sequencing to analyze all exons, flanks, 5' and 3' untranslated regions of F5 genes and the corresponding mutation site regions of family members, the mutation site was confirmed by reverse sequencing．The conservation of mutant amino acids was analyzed by ClustalX-2.1-win software. The PROVEAN and MutationTaster online bioinformatics software were used to predict the effect of mutation on protein function. Protein model and amino acid interaction at mutation sites was analyzed by Swiss-pdbviewer software. The PT and APTT of the proband were significantly prolonged compared with healthy controls (34.2 vs 13.2 s and 119.3 vs 36.0 s), while FⅤ∶C and FⅤ∶Ag extremely reduced (3% and 6%). The PT and APTT of the second-born, the third son, daughter, and grandson of the proband were slightly prolonged, and the FⅤ∶C and FⅤ∶Ag decreased to varying degrees. The related coagulant parameters of other family members were within normal range. Genetic analysis revealed that the proband had a c.911G>A heterozygous missense mutation on the exon 6 lead to p.Gly276Glu, and a c.5343C>G heterozygous missense mutation on the exon 16 lead to p.Ser1781Arg of the proband. The second-born, the third son, and grandson of the proband carry p.Gly276Glu heterozygotes, and the daughter carries p.Ser1781Arg heterozygotes, while the other family members were wild-type. The results of conservative analysis indicated that p.Gly276 and p.Ser1781 were highly conserved in homologous species. The two bioinformatics software predicted the same results, PROVEAN (score -6.214 and -12.79) indicated that the compound heterozygous mutation was a harmful mutation; MutationTaster (score 0.976 and 0.999) suggested that these mutations might cause corresponding disease. p.Gly276Glu protein model analysis showed that, the Glu side chain was prolonged and the molecular weight became larger, which would increase the steric hindrance between it and the surrounding amino acids, affect the normal local folding of the FⅤ protein, and eventually lead to the decrease of protein activity and content. This paper can not provide analysis of the spatial structure of p.Ser1781Arg mutant protein because of the lack of X ray 3 D structure file of FⅤ exon 16. The new compound heterozygous mutations (p.Gly276Glu and p.Ser1781Arg) identified in this study are the main reasons for the decrease in the FⅤ level of the family, among which p.Ser1781Arg is rarely reported at home and abroad.

Biochemical and genetic characteristics of 40 neonates with carnitine deficiency.

Primary carnitine deficiency (PCD) is a rare fatty acid metabolism disorder that can cause neonatal death. This study aims to analyze carnitine levels and detect SLC22A5 gene in newborns with carnitine deficiency, to provide a basis for early diagnosis of PCD, and to explore the relationship between carnitine in blood and SLC22A5 genotype. A total of 40 neonates with low free carnitine (C0<10 μmol/L) in blood were the subjects of the study. SLC22A5 gene was detected by Sanger sequencing to analyze the value of carnitine, the results of gene test and their relationship. A total of 15 variants of SLC22A5 gene were detected, including 11 pathogenic or likely pathogenic variants and 4 variants of uncertain significance. There were 5 new mutations: c.288delG (p.G96fsX33), c.744_745insTCG (p.M258_L259insS), c.752A>G (p.Y251C), c.495 C>A (p.R165E), and c.1298T>C (p.M433T). We found 14 PCD patients including 2 homozygous mutations and 12 heterozygous mutations, 14 with 1 mutation, and 12 with no mutation among 40 children. The C0 concentration of children with SLC22A5 gene homozygous or complex heterozygous mutations was (4.95±1.62) μmol/L in the initial screening, and (3.90±1.33) μmol/L in the second screening. The C0 concentration of children with no mutation was (7.04±2.05) μmol/L in the initial screening, and (8.02±2.87) μmol/L in the second screening. There were significant differences between children with homozygous or compound heterozygous mutations and with no mutation in C0 concentration of the initial and the second screening (both P<0.05), as well as between children with truncated mutation and with untruncated mutation in C0 concentration of the initial screening (P=0.022). There are 5 new mutations which enriched the mutation spectrum of SLC22A5 gene. C0<5 μmol/L is highly correlated with SLC22A5 gene homozygous or compound heterozygous mutations. Children with truncated mutation may have lower C0 concentration than that with untruncated mutation in the initial screening.

A case of severe malnutrition infant with neonatal onset intractable diarrhea

BackgroundCongenital tufting enteropathy (CTE) is a rare disease that manifests as intractable diarrhea during the neonatal period which is associated with mutations of the epithelial cell adhesion molecule (EpCAM) gene.Case presentationA male infant who presented with vomiting, diarrhea, abdominal distention, malnutrition and growth failure was admitted to our department when he was 2 months old. His parents were healthy and nonconsanguineous. Etiologic examinations of stool, inflammatory markers, blood gas and electrolytes levels, serum albumin level, serum immunoglobin levels were all normal. And there was no indication for metabolic diseases. Additionally, gastrointestinal contrast did not reveal abnormality of gastrointestinal. The patient was diagnosed with intestinal malabsorptive syndrome and severe malnutrition without definite cause. He was on supportive treatment and nutritional therapy for 13 months. However, he did not gain weight obviously. He was discharged at the age of 15 months and was fed with partial hydrolyzed formula and rice paste at home. Three months later he developed hypoglycemia and severe respiratory infection. Finally, he died due to sepsis and multiple organs failure. The next generation sequencing revealed one homozygous mutation of EpCAM gene and one complex heterozygous mutation of TTC7A gene. He was diagnosed CTE according to the genetic results and clinical manifestations.ConclusionsCTE is rarely reported in Asia. Patients present with congenital diarrhea, poor weight gain and growth failure are recommended to perform endoscopy examination with proper immunohistochemistry study as early as possible, and genetic testing is necessary when suspecting congenital diarrhea and enteropathy.

Clinical and serum lipid profiles and LDLR genetic analysis of xanthelasma palpebrarum with nonfamilial hypercholesterolemia.

XP is a flat xanthoma that usually presents as bilateral, symmetrical, soft, yellowish papules over the eyelids. The etiology of XP is unknown, but it may be related to complex heterozygous mutations. To investigate the lipid profiles, important clinical characteristics, and low-density lipoprotein receptor (LDLR) gene mutation in the patients suffering from xanthelasma palpebrarum (XP) with nonfamilial hypercholesterolemia. The prospective study included 25 individuals of XP with nonfamilial hypercholesterolemia, and 30 controls neither with XP nor familial hypercholesterolemia (FH). Each one underwent detailed clinical examination, serum lipid profile, and LDLR gene detection at the 400th exon and the 1246th exon. In our study, patients with XP were often not present with FH and family history. The mean serum cholesterol (CHOL) (5.20±1.82) and the prevalence of carotid atherosclerosis (4.34±0.78) were significantly higher in study group, while there was no statistically significant difference between two groups in terms of triglyceride (TG) (P=.38) and low-density lipoprotein (LDL) (P=.23). Unusually, the mean levels of high-density lipoprotein (HDL) (1.59±0.31) in the study group were much higher than the controls (1.31±0.30), and the LDLR gene mutation was not found. Clinical and serum lipid profiles indicated that XP was sporadic and underlying lipid abnormalities especially higher HDL. XP did not occur with mutations in the LDLR gene at the two exons. We suggested too high HDL level may be contributed to pathogenesis of XP and XP is often not associated with FH.

Analysis of clinical prognosis and mutant gene phenotype in children with hemophagocytic lymphohistiocytosis

Objective To investigate the clinical manifestations, prognosis and gene mutation phenotypes of hemophagocytic lymphohistiocytosis(HLH)in children of our hospital. Methods The clinical data of 42 patients with HLH from April 2013 to December 2018, and the genetic data of 8 patients with familial HLH(FHL)were collected retrospectively.The age, clinical manifestation, laboratory examination, prognosis and the characteristics of gene mutation phenotype of patients with HLH and FHL were analyzed emphatically.Furthermore, the clinical manifestations and prognosis of patients with HLH were analyzed according to whether EB virus was infected. Results Among these 42 patients with HLH, the onset age was ranged from 1 month to 13 years old and most of them were younger than 5 years old.The main clinical manifestations included cytopenia, prolonged fever, enlargement of liver and spleen and lymph nodes enlargement and serosal effusion.Laboratory examination showed that lactate dehydrogenas, ferritin, erythrocyte sedimentation rate and triglyceride increased significantly.The survival rate of the group in ferritin exceeding 4 500 μg/L and non-chemotherapy was lower than that of the group of ferritin less than 4 500 μg/L and chemotherapy in clinical prognosis(P<0.05). Ten patients of them survived after chemotherapy, and 2 patients survived for 5 to 6 months after hematopoietic stem cell transplantation in FHL.Patients with EB virus infection were older than those without EB virus infection.They had longer fever duration and higher proportion of lymph nodes enlargement and ferritin more than 4 500 μg/L(P values were 0.01, 0.04, 0.03, 0.03 respectively). However, there was no significant difference in survival time between the two groups.Eight patients had mutations in UNC13D(50.00%), PRF1(25.00%), PRKDC(12.50%)and IL2RG(12.50%)genes respectively, and most of the mutations were complex heterozygous mutations(62.50%). All the mutations were originated from their parents. Conclusion HLH is characterized by cytopenia, prolonged fever, enlargement of liver and spleen.HLH is more common in children under 5 years old.The clinical manifestations of HLH with EB virus infection are more severe while the prognosis is not statistically significant.The incidence of FHL is higher.There are more UNC13D gene mutations and complex heterozygous mutations.Children with HLH should be detected and treated with standardized therapy as soon as possible.Hematopoietic stem cell transplantation is a good treatment for HLH, especially for FHL patients. Key words: Hemophagocytic syndrome; Exon sequencing; Gene mutation; EB virus infection; Prognosis

Study on six patients with 17α-hydroxylase/17, 20-lyase deficiency

Objective To improve the understanding of 17α-hydroxylase/17, 20-lyase deficiency(17OHD)disease. Methods The clinical data of six patients suffering from 17OHD were analyzed retrospectively. Results Two patients with complete combined defect had typical clinical presentations, including absence of secondary sexual characteristics, primary amenorrhea, hypertension, hypokalamia, lower gonadal hormone levels, as well as elevated corticotropin and progesterone levels. TAC329AA homozygous mutation, IVS1+ 2T>C, and c. 775_776delAT complex heterozygous mutation were found in 2 cases. Four cases of partial combined defect showed high progesterone, lower gonadal hormones and dehydroepiandrosterone-sulfate levels. Three females(46, XX)showed spontaneous menstrual and primary infertility, and two of them got successful pregnancy with assisted reproductive technology. TAC329AA heterozygous mutation was found in those 4 cases. Conclusions TAC329AA mutation is common in 17OHD, and heterozygous or homozygous mutation of TAC329AA may be the genetic and molecular basis for determining whether these patients present as partial or complete defect. The elevated plasma progesterone in non-pregnancy combined with lower gonadal hormones and dehydroepiandrosterone-sulfate is the main character of patients with partial 17OHD. Less severe patients may be able to get successful pregnancy with assisted reproductive technology. Key words: 17α-hydroxylase/17, 20-lyase deficiency; CYP17A1 gene; Progesterone; Dehydroepiandrosterone-sulfate

Two pedigrees with arrhythmogenic right ventricular cardiomyopathy linked with R49H and F531C mutation in DSG2

Arrhythmogenic right ventricular cardiomyopathy (ARVC) presents as the progressive fibrofatty replacement of the cardiomyocytes particularly in the right ventricular wall. Here, we report two cases with ARVC. In family A, the proband carries a Desmoglein2 (DSG2) gene complex heterozygous mutation NM_001943.4:c.146G>A/p.(Arg49His)and NM_001943.3:c.1592T>G/p.(Phe531Cys). In family B, the proband carries a homozygous mutation NM_001943.3:c.1592T>G/p.(Phe531Cys).

Gene mutation and clinical analysis of nephronophthisis diagnosed using whole exome sequencing: Experience from China .

Nephronophthisis (NPH) is an autosomal recessive cystic kidney disease. Its onset is obscure, and its early clinical manifestations and pathological changes lack specificity, which makes clinical diagnosis difficult. At present, as many as 90 genetic alterations can result in NPH, which exhibits significant genetic heterogeneity. Therefore, high-throughput sequencing technology provides an effective method to identify and characterize novel NPH pathogenic genes when compared to Sanger sequencing. This study summarizes the gene mutations and clinical data of whole exome sequencing, which was used to diagnose 5 NPH patients to improve the understanding of the causative genes and clinical phenotypes of NPH. The clinical manifestations, laboratory examination indexes, and imaging data of 5 patients of NPH were reported. Whole exome sequencing was performed in 5 children, and the causative genes and mutation sites were analyzed by bioinformatics and genetics. The mutation sites were verified in children and their parents using Sanger direct sequencing. Among the 5 patients (3 male and 2 female), 2 patients had infantile NPH, and 3 patients had juvenile NPH. The 2 infantile NPH patients were characterized by the onset of liver dysfunction accompanied by hypertension and left ventricular change, and the renal function progressed to end-stage renal disease (ESRD) after 7months and 9months, respectively. The 2 cases of infantile NPH had NPHP3 mutations, with one carrying compound heterozygous mutations (c.1358A>G, c.2369A>G) and the other simultaneously carrying a c.1174C>T IVS26-3A>G cleavage site mutation from the father and a nonsense mutation (p.392R>X, 939) from the mother. The 2 juvenile NPH children had entered ESRD at the onset of the disease, including 1 patient with Joubert syndrome. The 2 patients with juvenile NPH had frameshift mutations (c.1583 to 1596: deletion) and homozygous point mutations (7 c.640G>T) of the NPHP1 gene. In addition, another patient with frequent urination and nocturia resulting in stage CKD3 renal function had a complex heterozygous mutation of the NPHP2 gene (c.2686G>A, c.1943A>G). The urine A1MU/creatinine and urinary transferrin increased in all 5 patients without hematuria. Whole exome sequencing identified the causative genes of NPH in 5 children. In NPH children with NPHP3 gene mutations, renal functional damage was characterized by early onset and rapid progression to ESRD, often accompanied by liver dysfunction and hypertension.