Clinical and laboratory features compared between JAK2 exon12 and JAK2 V617F mutated polycythemia vera / 中华血液学杂志

Objective: To compare clinical and laboratory features between JAK2 exon12 and JAK2 V617F mutated polycythemia vera (PV) . Method: We collected data from 570 consecutive newly-diagnosed subjects with PV and JAK2 mutation, and compared clinical and laboratory features between patients with JAK2 exon12 and JAK2 V617F mutation. Results: 543 (95.3%) subjects harboured JAK2 V617F mutation (JAK2 V617F cohort) , 24 (4.2%) harboured JAK2 exon12 mutations (JAK2 exon12 cohort) , and 3 (0.5%) harboured JAK2 exon12 and JAK2 V617F mutations. The mutations in JAK2 exon12 including deletion (n=10, 37.0%) , deletion accompanied insertion (n=10, 37.0%) , and missense mutations (n=7, 25.9%) . Comparing with JAK2 V617F cohort, subjects in JAK2 exon12 cohort were younger [median age 50 (20-73) years versus 59 (25-91) years, P=0.040], had higher RBC counts [8.19 (5.88-10.94) ×10(12)/L versus 7.14 (4.11-10.64) ×10(12)/L, P<0.001] and hematocrit [64.1% (53.7-79.0%) versus 59.6% (47.2%-77.1%) , P=0.001], but lower WBC counts [8.29 (3.2-18.99) ×10(9)/L versus 12.91 (3.24-38.3) ×10(9)/L, P<0.001], platelet counts [313 (83-1433) ×10(9)/L versus 470 (61-2169) ×10(9)/L, P<0.001] and epoetin [0.70 (0.06-3.27) versus 1.14 (0.01-10.16) IU/L, P=0.002] levels. We reviewed bone marrow histology at diagnosis in 20 subjects with each type of mutation matched for age and sex. Subjects with JAK2 exon12 mutations had fewer loose megakaryocyte cluster (40% versus 80%, P=0.022) compared with subjects with JAK2 V617F. The median follow-ups were 30 months (range 4-83) and 37 months (range 1-84) for cohorts with JAK2 V617F and JAK2 exon12, respectively. There was no difference in overall survival (P=0.422) and thrombosis-free survival (P=0.900) . Conclusions: Compared with patients with JAK2 V617F mutation, patients with JAK2 exon12 mutation were younger, and had more obvious erythrocytosis and less loose cluster of megakaryocytes.

Clinical phenotype and gene mutation analysis of 12 patients with hereditary protein C deficiency in different families / 中华血液学杂志

Objective: To investigate the molecular pathogenesis and clinical features of unrelated 12 patients with inherited coagulation protein C (PC) deficiency in Chinese population. Methods: The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and enzyme linked immunosorbent assay, respectively. The nine exons and flanking sequences of the protein C (PROC) gene were amplified by polymerase chain reaction with direct sequencing, and the suspected mutations were validated by reverse sequencing (clone sequencing for deletion mutations) . Results: The PC:A of the 12 probands decreased significantly, ranging from 18% to 55%, and the PC:Ag of the 10 probands decreased significantly. Eleven mutations were found, out of which four mutations [c.383G>A (p.Gly128Asp) , c.997G>A (p.Ala291Thr) , c.1318C>T (p.Arg398Cys) , and c.532G>C (p.Leu278Pro) ] were discovered for the first time. Six mutations were in the serine protease domain, four mutations were located in epidermal growth factor (EGF) -like domains, and one mutation was located in activation peptide. There were two deletion mutations (p.Met364Trp fsX15 and p.Lys192del) , and the rest were missense mutations. Mutations p.Phe181Val and p.Arg189Trp were identified in three unrelated families. All mutations may be inherited, and consanguineous marriages were reported in two families. Among the probands, nine cases had venous thrombosis, two cases had poor pregnancy manifestations, and one case had purpura. Conclusion: Patients with PC deficiency caused by PROC gene defects are prone to venous thrombosis, especially when there are other thrombotic factors present at the same time.

A recurrent homozygous missense mutation in CCDC103 causes asthenoteratozoospermia due to disorganized dynein arms / 亚洲男科学杂志(英文版)

Asthenoteratozoospermia is one of the most severe types of qualitative sperm defects. Most cases are due to mutations in genes encoding the components of sperm flagella, which have an ultrastructure similar to that of motile cilia. Coiled-coil domain containing 103 (CCDC103) is an outer dynein arm assembly factor, and pathogenic variants of CCDC103 cause primary ciliary dyskinesia (PCD). However, whether CCDC103 pathogenic variants cause severe asthenoteratozoospermia has yet to be determined. Whole-exome sequencing (WES) was performed for two individuals with nonsyndromic asthenoteratozoospermia in a consanguineous family. A homozygous CCDC103 variant segregating recessively with an infertility phenotype was identified (ENST00000035776.2, c.461A>C, p.His154Pro). CCDC103 p.His154Pro was previously reported as a high prevalence mutation causing PCD, though the reproductive phenotype of these PCD individuals is unknown. Transmission electron microscopy (TEM) of affected individuals' spermatozoa showed that the mid-piece was severely damaged with disorganized dynein arms, similar to the abnormal ultrastructure of respiratory ciliary of PCD individuals with the same mutation. Thus, our findings expand the phenotype spectrum of CCDC103 p.His154Pro as a novel pathogenic gene for nonsyndromic asthenospermia.

A child with diffuse mesangial sclerosis caused by a missense mutation of TRPC6 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology and clinical outcome of a child with steroid-resistant nephrotic syndrome and diffuse mesangial sclerosis.@*METHODS@#Genomic DNA was extracted from peripheral blood leukocytes of the proband and his parents. Targeted capture - next generation sequencing and Sanger sequencing were carried out. Candidate variant was verified by segregation analysis in his family.@*RESULTS@#A heterozygous missense variant of the TRPC6 gene, namely c.325G>A (p.Gly109Ser), was detected in the proband. The same variant was not detected in either parent. According to the guidelines for the interpretation of sequence variants developed by American College of Medical Genetics and Genomics, the variant was predicted as pathogenic.@*CONCLUSION@#The missense variant of the TRPC6 gene probably underlay the diffuse mesangial sclerosis in this patient. Above finding has expanded the phenotypic spectrum of the TRPC6 gene.

De novo ALX4 variant detected in child with non-syndromic craniosynostosis

Current understanding of the genetic factors contributing to the etiology of non-syndromic craniosynostosis (NSC) remains scarce. The present work investigated the presence of variants in ALX4, EFNA4, and TWIST1 genes in children with NSC to verify if variants within these genes may contribute to the occurrence of these abnormal phenotypes. A total of 101 children (aged 45.07±40.94 months) with NSC participated in this cross-sectional study. Parents and siblings of the probands were invited to participate. Medical and family history of craniosynostosis were documented. Biological samples were collected to obtain genomic DNA. Coding exons of human TWIST1, ALX4, and EFNA4 genes were amplified by polymerase chain reaction and Sanger sequenced. Five missense variants were identified in ALX4 in children with bilateral coronal, sagittal, and metopic synostosis. A de novo ALX4 variant, c.799G>A: p.Ala267Thr, was identified in a proband with sagittal synostosis. Three missense variants were identified in the EFNA4 gene in children with metopic and sagittal synostosis. A TWIST1 variant occurred in a child with unilateral coronal synostosis. Variants were predicted to be among the 0.1% (TWIST1, c.380C>A: p. Ala127Glu) and 1% (ALX4, c.769C>T: p.Arg257Cys, c.799G>A: p.Ala267Thr, c.929G>A: p.Gly310Asp; EFNA4, c.178C>T: p.His60Tyr, C.283A>G: p.Lys95Glu, c.349C>A: Pro117Thr) most deleterious variants in the human genome. With the exception of ALX4, c.799G>A: p.Ala267Thr, all other variants were present in at least one non-affected family member, suggesting incomplete penetrance. Thus, these variants may contribute to the development of craniosynostosis, and should not be discarded as potential candidate genes in the diagnosis of this condition.

Performance of mutation pathogenicity prediction tools on missense variants associated with 46, XY differences of sex development

OBJECTIVES: Single nucleotide variants (SNVs) are the most common type of genetic variation among humans. High-throughput sequencing methods have recently characterized millions of SNVs in several thousand individuals from various populations, most of which are benign polymorphisms. Identifying rare disease-causing SNVs remains challenging, and often requires functional in vitro studies. Prioritizing the most likely pathogenic SNVs is of utmost importance, and several computational methods have been developed for this purpose. However, these methods are based on different assumptions, and often produce discordant results. The aim of the present study was to evaluate the performance of 11 widely used pathogenicity prediction tools, which are freely available for identifying known pathogenic SNVs: Fathmn, Mutation Assessor, Protein Analysis Through Evolutionary Relationships (Phanter), Sorting Intolerant From Tolerant (SIFT), Mutation Taster, Polymorphism Phenotyping v2 (Polyphen-2), Align Grantham Variation Grantham Deviation (Align-GVGD), CAAD, Provean, SNPs&GO, and MutPred. METHODS: We analyzed 40 functionally proven pathogenic SNVs in four different genes associated with differences in sex development (DSD): 17β-hydroxysteroid dehydrogenase 3 (HSD17B3), steroidogenic factor 1 (NR5A1), androgen receptor (AR), and luteinizing hormone/chorionic gonadotropin receptor (LHCGR). To evaluate the false discovery rate of each tool, we analyzed 36 frequent (MAF>0.01) benign SNVs found in the same four DSD genes. The quality of the predictions was analyzed using six parameters: accuracy, precision, negative predictive value (NPV), sensitivity, specificity, and Matthews correlation coefficient (MCC). Overall performance was assessed using a receiver operating characteristic (ROC) curve. RESULTS: Our study found that none of the tools were 100% precise in identifying pathogenic SNVs. The highest specificity, precision, and accuracy were observed for Mutation Assessor, MutPred, SNP, and GO. They also presented the best statistical results based on the ROC curve statistical analysis. Of the 11 tools evaluated, 6 (Mutation Assessor, Phanter, SIFT, Mutation Taster, Polyphen-2, and CAAD) exhibited sensitivity >0.90, but they exhibited lower specificity (0.42-0.67). Performance, based on MCC, ranged from poor (Fathmn=0.04) to reasonably good (MutPred=0.66). CONCLUSION: Computational algorithms are important tools for SNV analysis, but their correlation with functional studies not consistent. In the present analysis, the best performing tools (based on accuracy, precision, and specificity) were Mutation Assessor, MutPred, and SNPs&GO, which presented the best concordance with functional studies.

17 beta-hydroxysteroid dehydrogenase 3 deficiency due to novel compound heterozygous variants of HSD17B3 gene in a sib pair / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a sib pair featuring 17beta-hydroxysteroid dehydrogenase type 3 deficiency.@*METHODS@#Genomic DNA was extracted from the proband, her sister, and their parents, and was subjected to sequencing analysis with a gene panel for sexual development. Suspected variant was verified by Sanger sequencing and bioinformatic analysis.@*RESULTS@#Both the proband and her sister were found to harbor novel compound heterozygous missense variants of the HSD17B3 gene, namely c.839T>C (p.Leu280Pro) and c.239G>T (p.Arg80Leu), which were derived respectively from their mother and father. The variants were unreported previously and predicted to be deleterious by PolyPhen2, MutationTaster and other online software. Based on the American College of Medical Genetics and Genomics standards and guidelines, both c.839T>C(p.Leu280Pro) and c.239G>T (p.Arg80Leu) were predicted to be likely pathogenic (PM2+PP1+PP2+PP3+PP4, PM2+PM5+PP1+PP2+PP3+PP4).@*CONCLUSION@#The compound heterogeneous variants of the HSD17B3 gene probably underlay the disease in this sib pair. 17beta-hydroxysteroid dehydrogenase type 3 deficiency may lack specific clinical features and laboratory index, genetic testing can facilitate a definitive diagnosis.

A study on KIF1A gene missense variant analysis and its protein expression and structure profiles of an autism spectrum disorder family trio / 中华医学遗传学杂志

OBJECTIVE@#To analyze the pathogenic variants of the KIF1A gene and its corresponding protein structure in an autism spectrum disorder (ASD) family trio carrying harmful missense variants in the KIF1A gene.@*METHODS@#The peripheral blood DNA of the patient and his parents was extracted and sequenced using whole exome sequencing (WES) technology and verified by Sanger sequencing. Bioinformatics software SIFT, PolyPhen-2, Mutation Taster, and CADD software were used to analyze the harmfulness and conservation of variants. The Human Brain Transcriptome (HBT) database was used to analyze the expression of the KIF1A gene in the brain. PredictProtein and SWISS-MODEL were further used to predict the secondary structure and tertiary structure of KIF1A wild-type protein and variant protein. PyMOL V2.4 was utilized to investigate the change of hydrogen bond connection after protein variant.@*RESULTS@#The WES sequencing revealed a missense variant c.664A>C (p.Asn222His) in the child's KIF1A gene, and this variant was a de novo variant. The harmfulness prediction results suggest that this variant is harmful. By analyzing expression level of KIF1A gene in the brain. It is found that KIF1A gene widely expressed in various brain regions during embryonic development. By analyzing the variant protein structure, the missense variant of KIF1A will cause many changes in the secondary structure of protein, such as alpha-helix, beta-strand, and protein binding domain. The connection of hydrogen bond and spatial structure will also change, thereby changing the original biological function.@*CONCLUSION@#The KIF1A gene may be a risk gene for ASD.

Identification of two novel variants of the PCCB gene in a pedigree affected with propionic acidemia / 中华医学遗传学杂志

OBJECTIVE@#To detect pathogenic variants in a pedigree affected with propionic acidemia (PA).@*METHODS@#The proband was subjected to high-throughput next-generation sequencing. Suspected variants were validated by Sanger sequencing of his family members. mRNA was extracted from peripheral blood lymphocytes from the proband's father in order to verify the impact of the splicing variant by RT-PCR combined with Sanger sequencing. The pathogenicity of the missense variant was predicted by using PolyPhen-2, Mutation Taster, SIFT, COBALT and HOPE software.@*RESULTS@#The proband was found to harbor compound heterozygous variants of the PCCB gene, namely c.184-2A>G and c.733G>A (p.G245S), which were respectively inherited from his father and mother. RT-PCR combined with Sanger sequencing confirmed skipping of exon 2 during transcription. Bioinformatic analysis indicated the c.733G>A (p.G245S) variant to be damaging.@*CONCLUSION@#The two variants of the PCCB gene probably underlay the disease in this patient. Above findings have enriched the spectrum of PCCB gene variants.

Genetic analysis of a child with co-commitment progressive multifocal leukoencephalopathy and X-linked hyper IgM syndrome / 中华医学遗传学杂志

OBJECTIVE@#To detect variant of the CD40L gene and infection of Jamestown Canyon virus (JCV) in a 7-year-and-9-month-old boy with co-commitment progressive multifocal leukoencephalopathy (PML) and X-linked hyper IgM syndrome (XHIGM).@*METHODS@#Peripheral blood samples of the child and his parents were collected for the extraction of genomic DNA. The 5 exons and exon/intronic boundaries of the CD40L gene were subjected to PCR amplification and sequencing. Suspected variants were analyzed by using bioinformatic software. The JCV gene was amplified from genomic DNA by nested PCR and sequenced.@*RESULTS@#The child was found to harbor a hemizygous c.506 A>C (p.Y169S) missense variant in exon 5 of the CD40L gene. The variant may affect the TNFH domain of the CD40L protein and result in structural instability and loss of hydrophobic interaction between CD40L and CD40. As predicted by PolyPhen2 and SIFT software, the variant was probably damaging (score = 1.00) and deleterious (score= -8.868). His mother was found to be a heterozygous carrier, while the same variant was not found in his father. Gel electrophoresis of the nested PCR product revealed presence of target JCV band, which was confirmed to be 99% identical with the JCV gene by sequencing.@*CONCLUSION@#The patient was diagnosed with co-commitment XHIGM and PML based on the testing of the CD40L gene and JCV infection.

Analysis of MCCC2 gene variant in a pedigree affected with 3-methylcrotonyl coenzyme A carboxylase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with clinically suspected 3-methylcrotonyl-coenzyme A carboxylase deficiency (MCCD).@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the proband and her parents. Whole exome sequencing was used to screen pathogenic variant in the proband. Suspected variant was verified by Sanger sequencing. Impact of the variant on the structure and function of protein product was analyzed by using bioinformatic software.@*RESULTS@#Sanger sequencing showed that the proband has carried homozygous missense c.1342G>A (p.Gly448Ala) variant of the MCCC2 gene, for which her mother was a heterozygous carrier. The same variant was not detected in her father. The variant was predicted to be pathogenic by PolyPhen-2 and Mutation Taster software, and the site was highly conserved among various species. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.1342G>A (p.Gly448Ala) variant of MCCC2 gene was predicted to be likely pathogenic(PM2+PP2-PP5).@*CONCLUSION@#The homozygous missense variant of the MCCC2 gene c.1342G>A (p.Gly448Ala) probably underlay the molecular pathogenesis of the proband. Genetic testing has confirmed the clinical diagnosis.

Identification of pathogenic variant in a Chinese pedigree affected with non-syndromic cleft lip and palate / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with non-syndromic cleft lip and cleft palate (NSCLP).@*METHODS@#With informed consent obtained, members of the pedigree were subjected to clinical examination and history taking to exclude syndromic cleft lip and palate. One affected member was subjected to whole-exome sequencing and bioinformatics analysis. Candidate variant was verified by Sanger sequencing and co-segregation analysis of her family members and 100 unrelated healthy individuals.@*RESULTS@#Whole-exome sequencing and co-segregation analysis showed that all affected members of this pedigree have carried a heterozygous missense c.253A>G (p.Cys85Arg) variant in exon 4 of the IRF6 gene, which has co-segregated with the phenotype and was not found among the 100 unrelated healthy individuals.@*CONCLUSION@#The missense c.253A>G variant in exon 4 of the IRF6 gene probably underlay the NSCLP in this pedigree.

Serological and molecular study of a novel B(A) allele with multiple missense mutations / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular basis for an individual suspected as AwB subtype through DNA sequencing.@*METHODS@#ABO serology was carried out with the standard tube method. To identify the ABO gene haplotype, the amplicons of exon 7 were cloned and sequenced.@*RESULTS@#Serological results showed that the forward typing was AwB and the reverse typing was B. Sequencing analysis revealed that the sample has contained an O01 allele in addition with c.297A>G, c.657C>T, c.796C>A, c.803G>C, c.930G>A variants as compared with the A101 allele.@*CONCLUSION@#Through sequencing analysis, the sample with an AwB subtype by serological testing was identified as a novel B(A) phenotype, which was unreported previously.

Different Subtypes Caused by c.721C>T Substitution in the Exon 7 of ABO Gene / 中国实验血液学杂志

OBJECTIVE@#To analyze the different subtypes caused by c.721C>T substitution in the exon 7 of the ABO gene, and to investigate the related molecular mechanism of different antigens expression.@*METHODS@#ABO subtypes in 7 samples were identified by standard serological methods. The exons 6, 7, and adjacent intron of ABO gene were amplified by Polymerase Chain Reaction (PCR), and the PCR products were analyzed by direct DNA sequencing and cloning sequencing.@*RESULTS@#ABO subtypes phenotypes were A@*CONCLUSION@#c.721C>T substitution in the ABO gene causes p.Arg241Trp exchange resulting in the decreasing of GTA or GTB activities and weaker antigen expression. O.01.07 is a null allele which cannot form a functional catalytic enzyme has no effect on A

Analysis of SIK3 gene variation in a boy with autism spectrum disorder complicated with epilepsy / 中华医学遗传学杂志

OBJECTIVE@#To study the genetic variants of a child with Autism Spectrum Disorder (ASD) combined with epilepsy, and explore its possible pathogenic mechanism.@*METHODS@#Clinical data of the child were collected and evaluated, whole-exome sequencing (WES) technology was used to explore the genetic variants sites of the child and his parents and candidate genes were filtered out. Sanger sequencing were performed to verify the variants identified by WES and PolyPhen2 was utilized to predict the function of these variants. qPCR was carry out to determine the expression of the variant gene.@*RESULTS@#The proband carried a compound heterozygous mutation in the SIK3 gene (Chr11 q23.3, NM_025164.6), which contains a missense mutation c.1295A>G (p.N432S) inherited from the father and a deletion [c.2389_2391del(p.797del)] inherited from the mother. Both mutation sites are highly conservative, and PolyPhen2 predicted (c.1295A>G [p.N432S]) to be harmful. Compared to the mother, expression of SIK3in mRNA level in the peripheral blood of the proband and his father were both significantly decreased; compared to normal child, SIK3 expression in the peripheral blood of the proband and two other children with ASD were all decreased significantly too. In addition, studies on mice found that Sik3 gene has a marked higher level of expression in the brain.@*CONCLUSION@#The SIK3 gene variants may probably be associated with ASD. The detailed mechanism needs to be studied further, which may involve lipid metabolism dysfunction in the brain.

Variante patogénica en el gen PCDH19 en una paciente con epilepsia y discapacidad cognitiva / Pathogenic variant in the PCDH19 gene in a patient with epilepsy and cognitive disability

INTRODUCCIÓN: La asociación de casos familiares de epilepsia y discapacidad intelectual (DI) en mujeres fue reportada en 1971. El año 2008, se identificó el rol de variantes patogénicas del gen PCDH19 en algunas familias. La enfermedad se presenta con crisis febriles en cluster, DI y rasgos autistas. La mayoría se debe a variantes de novo, pero hay algunos casos heredados por un modo peculiar de transmisión ligada X. OBJETIVO: Comunicar el caso de una paciente con epilepsia portadora de una variante patogénica en el gen PCDH1 9, revisando la historia natural de la enfermedad y la evidencia disponible para su manejo. CASO CLÍNICO: Paciente femenina, con antecedentes de embarazo y período perinatal normal. A los 6 meses, estando febril, presentó crisis focales motoras en cluster que repitieron a los 14, 18, 21 meses y 3 años siempre asociadas a fiebre, presentando incluso estatus epiléptico. Mantiene biterapia con topiramato y ácido valproico, completando 13 años sin crisis. El estudio del gen SCN1A no mostró anomalías y el estudio del gen PCDH19 reveló una variante patogénica en heterocigosis, "de novo". La paciente ha evolucionado con DI y alteraciones conductuales severas que requieren aten ción de salud mental. CONCLUSIONES: Las variantes patogénicas PCDH19 tienen expresión fenotípica variada. El diagnóstico genético debe sospecharse con la clínica. La morbilidad psiquiátrica a largo plazo puede ser incapacitante.

INTRODUCTION: The association of family cases of epilepsy and intellectual disability in women was reported in 1971. In 2008, the role of pathogenic variants of the PCDH19 gene in some families were identified. The disease presents with febrile seizure clusters, intellectual disability, and autistic features. Most cases are due to de novo variants, however, there are some inherited cases, with an atypical way of X-linked transmission. OBJECTIVE: To report the case of a patient with epilepsy carrier of a pathogenic variant of the PCDH19 gene, reviewing the natural history of this condition and the available evidence for its management. CLINICAL CASE: Female patient, with normal history of pregnancy and perinatal period. At 6 months, while febrile, she presented focal motor seizure clusters that repeated at 14, 18, 21 months and 3 years old, always associated with fever, even presenting status epilepticus. She is on therapy with topiramate and valproic acid, achieving 13 seizure-free years. The analysis of the SCN1A gene showed no abnormalities and the study of the PCDH19 gene revealed a de novo heterozygous pathogenic variant. The patient evolved with intellectual disability and severe behavioral disorders that require mental health team support. CONCLUSIONS: PCDH19 pathogenic variants have varied phenotypic expression. The genetic diagnosis should be guided with the clinical features. Long-term psychiatric morbidity can be disabling.

Identification of mutations in the pah gene in pku patients in the state of mato grosso / Identificação de mutações no gene da pah em pacientes com fenilcetonúria do estado de mato grosso

ABSTRACT Objective: To identify phenylalanine hydroxylase (PAH) mutations in patients with phenylketonuria (PKU) from the Newborn Screening Service in Mato Grosso, Midwest Brazil. Methods: This is a cross-sectional descriptive study. The sample consisted of 19 PKU patients diagnosed by newborn screening. Molecular analysis: DNA extraction using the "salting-out" method. Detection of IVS10nt-11G>A, V388M, R261Q, R261X, R252W, and R408W mutations by the restriction fragment length polymorphism (RFLP) technique. Results: Two mutant alleles were identified in four patients (21.1%), one allele in five patients (26.2%), and none in the remaining ten patients (52.6%). A total of 13/38 alleles were detected, corresponding to 34.2% of the PAH alleles present. The most prevalent variant was V388M (13.2% of the alleles), followed by R261Q (10.1%) and IVS10nt-11G>A (7.9%). Three variants (R261X, R252W, and R408W) were not found. The most frequent mutation types were: missense mutation in eight alleles (18.4%) and splicing in four alleles (10.5%). The model proposed by Guldberg to determine a genotype/phenotype correlation was applied to four classical PKU patients with two identified mutations. In three of them, the predicted moderate/moderate or moderate PKU phenotype did not coincide with the actual diagnosis. The prediction coincided with the diagnosis of one classic PKU patient. The estimated incidence of PKU for Mato Grosso, Brazil, was 1:33,342 live births from 2003 to 2015. Conclusion: The only mutations found in the analyzed samples were the IVS10nt-11G>A, V388M, and R261Q. The genotype/phenotype correlation only occurred in four (5.3%) patients.

RESUMO Objetivo: Identificar mutações da fenilalanina hidroxilase (PAH) em pacientes com PKU (fenilcetonúria) do Serviço de Triagem Neonatal em Mato Grosso. Métodos: Estudo de corte transversal. Amostra composta de 19 pacientes com PKU através do exame de triagem neonatal biológica. Análise molecular: a) extração de DNA pela metodologia "salting out". B) detecção de mutações IVS10nt-11G>A, V388M, R261Q, R261X, R252W e R408W pela técnica de polimorfismo de comprimento de fragmento de restrição (RFLP). Resultados: Dois alelos foram identificados em quatro pacientes (21,1%), um alelo em cinco pacientes (26,2%) e nenhum nos dez pacientes restantes (52,6%). Um total de 13/38 alelos foram identificados, correspondendo a 34,2% dos alelos PAH presentes. A variante mais prevalente foi a V388M (13,2% dos alelos), seguida de R261Q (10,1%) e IVS10nt-11G>A (7,9%). Três variantes (R261X, R252W e R408W) não foram encontradas. Os tipos de mutações mais frequentes foram: troca de sentido em oito alelos (18,4%) e emenda em quatro alelos (10,5%). O modelo proposto por Guldberg para determinar uma correlação genótipo/fenótipo foi aplicado para quatro pacientes clássicos de PKU, com duas mutações identificadas. Em três, o fenótipo previsto de PKU moderada/moderada ou moderada não coincidiu com o diagnóstico real. A predição coincidiu com o diagnóstico de um paciente PKU clássico. A incidência de PKU estimada para Mato Grosso, Brasil foi de 1:33.342 nascidos vivos para o período de 2003 a 2015. Conclusões: Foram encontradas apenas as mutações IVS10nt-11G>A, V388M, R261Q nas amostras analisadas. A correlação genótipo/fenótipo ocorreu em quatro (5,3%) pacientes.

Identification of a novel missense NIPBL variant in a juvenile with severe type of Cornelia de Lange syndrome / 中华医学遗传学杂志

OBJECTIVE@#To detect pathogenic variant in a juvenile with severe type Cornelia de Lange syndrome (CdLS).@*METHODS@#A 12-year-old female presented with comprehensive developmental retardation and deformity of lower limbs. Genomic DNA was extracted from peripheral blood sample of the patient. Whole exome sequencing was performed to identify pathogenic variants. Putative variant was verified by Sanger sequencing. The impact of variants was predicted and validated by bioinformatic analysis.@*RESULTS@#A de novo missense variant, c.1507A>G (p. Lys503Glu), was found in the NIPBL gene of the proband. The variant was unreported previously and predicted to be pathogenic by PolyPhen-2, MutationTaster and SIFT. Using HomoloGene system, the 503 loci in the NIPBL protein are highly conserved. The change of amino acid (Glu), locating in 503 locus, was found to cause the Neuromodulin_N superfamily domain destroyed, resulting in severe damage to the function of NIPBL protein.@*CONCLUSION@#The de novo missense variant c.1507A>G (p. Lys503Glu) of the NIPBL gene probably underlies the disease in this patient.

Clinical features and gene variant of a pedigree affected with X-linked recessive mental retardation Claes-Jensen type / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a pedigree affected with X-linked recessive mental retardation Claes-Jensen type.@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the patient, his parents (phenotypically normal) and two elder brothers with similar clinical manifestations. Whole exome sequencing was carried out for the proband, and the result was verified by Sanger sequencing.@*RESULTS@#The proband was found to harbor a hemizygous c.1565C>T missense variant in exon 11 of the KDM5C gene. The transition has resulted in replacement of serine by phenylalanine at position 522 (p.Ser522Phe). Sanger sequencing showed that the patient's two elder brothers and mother carried the same variant, which was predicted to be probably damaging by SIFT, PolyPhen2 and Mutation_Taster. The three affected brothers presented with similar clinical phenotypes characterized by mental retardation, speech delay, behavioral problem, self-limited epilepsy responsible to medication, short stature and microcephaly. The mother only had mild cognitive impairment and learning disability. The same variant was not found in their father and was unreported previously.@*CONCLUSION@#The c.1565C>T (p.Ser522Phe) of the KDM5C gene probably underlay the X-linked recessive mental retardation Claes-Jensen type in this pedigree.

Missense Mutations in the CTSC Gene in Saudi Families Segregating Papillon-Lefèvre Syndrome

No abstract available.