Phenotypic and genetic analysis of a child with partial trisomy 7q / 中华医学遗传学杂志

OBJECTIVE@#To define the nature and origin of a chromosomal aberration in a child with unexplained growth and development retardation, and to analyze its genotype-phenotype correlation.@*METHODS@#A child who had presented at the Affiliated Children's Hospital of Zhengzhou University on July 9, 2019 was selected as the study subject. Chromosomal karyotypes of the child and her parents were determined with routine G-banding analysis. Their genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array).@*RESULTS@#Karyotyping analysis combined with SNP array suggested that the chromosomal karyotype of the child was 46,XX,dup(7)(q34q36.3), whilst no karyotypic abnormality was found in either of her parents. SNP array has identified a de novo 20.6 Mb duplication at 7q34q36.3 [arr[hg19] 7q34q36.3(138335828_158923941)×3] in the child.@*CONCLUSION@#The partial trisomy 7q carried by the child was rated as a de novo pathogenic variant. SNP array can clarify the nature and origin of chromosomal aberrations. Analysis of the correlation between genotype and phenotype can facilitate the clinical diagnosis and genetic counseling.

A case of Coffin-Siris syndrome type 1 due to 6q25.3 deletion / 中华神经科杂志

Clinical data and genetic mutation characteristics of a patient with Coffin-Siris syndrome by 6q25.3 deletion were summarized. The child was a 7-year and 6-month old girl who had feeding difficulties, repeated infection, language and motor retardation, low intelligence, laryngeal cartilage dysplasia, thick eyebrows, sparse teeth, hairy back, hyperactivity and aggressive behavior, seizures and ataxia. There was no abnormality in chromosomal karyotype analysis by proband; genomic copy number variant sequencing (CNV-seq) indicated approximately 4.27 Mb heterozygous deletion in chromosome 6q25.3 region, with 17 genes including ARID1B gene, father maternal CNV-seq showing no abnormalities. Trio-whole-exome sequencing showed the proband missed all exons 1-20 of the ARID1B gene, with wild-type parents. The proband had severe clinical symptoms and haplodose insufficiency which was the genetic etiology.

Analysis of a Chinese pedigree with autosomal dominant Charcot-Marie-Tooth disease type 2A2A / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a pedigree affected with peroneal muscular atrophy.@*METHODS@#Neuroelectrophysiological examination and whole exome sequencing were carried out for the proband, a six-year-and-ten-month-old boy. Suspected variant was verified in his family members through Sanger sequencing. Bioinformatic analysis was carried to predict the conservation of amino acid sequence and impact of the variant on the protein structure and function.@*RESULTS@#Electrophysiological examination showed demyelination and axonal changes of motor and sensory nerve fibers. A heterozygous missense c.1066A>G (p. Thr356Ala) variant was found in exon 11 of the MFN2 gene in the proband and his mother, but not in his sister and father. Bioinformatic analysis using PolyPhen-2 and Mutation Taster software predicted the variant to be pathogenic, and that the sequence of variation site was highly conserved among various species. Based no the American College of Medical Genetics and Genomics standards and guidelines, the c.1066A>G (p. Thr356Ala) variant of MFN2 gene was predicted to be likely pathogenic (PS1+ PM2+ PP3+ PP4).@*CONCLUSION@#The heterozygous missense c.1066A>G (p.Thr356Ala) variant of the MFN2 gene probably underlay the disease in the proband, and the results have enabled genetic counseling and prenatal diagnosis for this family.

Analysis of NF1 gene variants among thirteen patients with neurofibromatosis type 1 / 中华医学遗传学杂志

OBJECTIVE@#To detect variants of NF1 gene among thirteen patients with neurofibromatosis type 1.@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the patients. High-throughput sequencing was employed to detect potential variants of the NF1 and NF2 genes.@*RESULTS@#Thirteen pathogenic variants were identified among the patients, which included one NF1 deletion, three missense variants, three nonsense variants and six frameshifting variants. Among these, 10 variants have been associated with neurofibromatosis type 1. c.4180A>T (p.Asn1394Tyr), c.4217dupT (p.Leu1406fs) and c.1753dupT(p.Leu585Phefs*3) were unreported previously. Based on the guidelines of the American College of Medical Genetics and Genomics, c.4180A>T (p.Asn1394Tyr) was predicted to be likely pathogenic (PS2+PM1+PM2+PP2), while c.4217dupT (p.Leu1406fs) and c.1753dupT (p.Leu585Phefs*3) were predicted to be pathogenic (PVS1+PS2+PM2).@*CONCLUSION@#Variants of the NF1 gene probably underlay the disease among these children. Above findings have enriched the the spectrum of NF1 gene variants.

Clinical and genetic study of a child with delayed language development carrying ring 22 and a 22q13 microdeletion / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child featuring delayed language development.@*METHODS@#The patient was subjected to conventional G-banding chromosomal karyotyping and single nucleotide polymorphism microarray (SNP array) analysis.@*RESULTS@#The karyotype of the child was 46, XY, r(22)(p11.2q13). SNP array analysis has identified a hemizygous 1.67 Mb deletion at 22q13 (arr [Hg19]22q13.33 (49 531 302-51 197 766)×1).@*CONCLUSION@#The child has carried a ring 22 in addition with a 22q13 microdeletion. The results may provide clues for her condition and genetic counseling for the family.

Clinical and genetic analysis of a case with infantile Parkinsonism with motor delay due to tyrosine hydroxylase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic variants in a child with tyrosine hydroxylase-deficient infantile Parkinsonism with motor delay.@*METHODS@#Clinical feature of the patient was summarized. Genomic DNA was extracted from peripheral blood samples taken from the child and her family members. All exons of GCH1, TH and SPR genes were subjected to targeted capture and next-generation sequencing. Suspected variants were verified by Sanger sequencing.@*RESULTS@#The child could not sit alone at 7 month and 11 days. Physical examination suggested motor retardation and hypotonia, limb stiffness, head nodding, slight torticollis, and language and intellectual developmental delays. She developed involuntary shaking of limbs at 3 month old, which lasted approximately 10 seconds and aggregated with excitement and before sleeping. Cranial MRI revealed widening of subarachnoid space on the temporomandibular and particularly temporal sides. Genetic testing revealed that she has carried a nonsense c.457C>T (p.R153X) variant, which was known to be pathogenic, and a novel missense c.720C>G (p.I240M) variant of the TH gene. The two variants were derived from her father and mother, respectively.@*CONCLUSION@#The child was diagnosed as tyrosine hydroxylase-deficient infantile Parkinsonism with motor delay due to compound heterozygous variants of the TH gene. Above finding has enriched the spectrum of TH gene variants.

Phenotypic and genetic analysis of a boy with partial trisomy of 22q / 中华医学遗传学杂志

OBJECTIVE@#To delineate the nature and origin of chromosomal aberration in a boy with mental retardation and multiple congenital deformities.@*METHODS@#Chromosomal karyotypes of the proband and his parents were determined by routine G-banding analysis. Genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array).@*RESULTS@#The karyotype of the proband was 46,X,add(Y)(q11.23). No karyotypic abnormality was detected in either parent. SNP array has identified a de novo 21.6 Mb duplication at 22q12qter in the proband.@*CONCLUSION@#The de novo 22q12qter duplication probably underlies the abnormalities in the proband.

Phenotypic and genetic analysis of a boy with a 10p15.3 deletion and partial trisomy 18p syndrome / 中华医学遗传学杂志

OBJECTIVE@#To delineate the nature and origin of chromosomal aberration in a girl with mental retardation.@*METHODS@#Genomic DNA was analyzed by using single nucleotide polymorphism-based array (SNP array). The proband and her parents were subjected to routine G-banded chromosomal karyotyping analysis.@*RESULTS@#SNP array has identified a 1.2 Mb microdeletion at 10p15.3 and a duplication at 18p11.21-pter in the proband. The patient was also found to harbor a structural aberration involving 10p. The karyotype of her father was 46,XY,t(10;18)(p15;p11.2), while her mother was found to be normal.@*CONCLUSION@#The structural aberration of 10p carried by the patient has derived from her father whom has carried a balanced translocation of t(10;18). Her karyotype was finally determined as 46,XX,der(10)t(10;18)(p15;p11.2)pat. The abnormal phenotype of the patient can probably be attributed to the presence of 10p15.3 microdeletion and 18p11.21-pter duplication.

Clinical characteristics and genetic analysis of primary coenzyme Q10 deficiency caused by COQ4 gene mutation / 中华内分泌代谢杂志

Objective@#To explore the clinical and genetic characteristics of primary coenzyme Q10 deficiency caused by coenzyme Q4 (COQ4) variants.@*Methods@#Clinical data were collected, while COQ4 gene was sequenced.@*Results@#Here were reported a boy of 3 months old who came to our hospital presented with feeding difficulties, repeated respiratory infections, convulsions for 3 months. He was subsequently diagnosed as cerebral atrophy, and growth retardation. All exons were sequenced.c.211G>A(p.A71T, maternal), c. 436T>A(p.F146I, paternal) were detected. After treatment with coenzyme Q10, the convulsive symptoms improved significantly. Literature review revealed that totally 14 cases with primary coenzyme Q10 deficiency caused by COQ4 gene mutation were reported. The onset age varies from neonatal to 18 years old, and the clinical manifestations are heterogeneous, including cardiomyopathy, epilepsy, ataxia, cerebellar atrophy, respiratory insufficiency, and growth retardation.@*Conclusion@#For cases with atypical clinical manifestations of primary coenzyme Q10 deficiency, gene detection is helpful for an early diagnosis and treatment.

Clinical characteristics and genetic analysis of primary coenzyme Q10 deficiency caused by COQ4 gene mutation / 中华内分泌代谢杂志

Objective To explore the clinical and genetic characteristics of primary coenzyme Q10 deficiency caused by coenzyme Q4 ( COQ4) variants. Methods Clinical data were collected, while COQ4 gene was sequenced. Results Here were reported a boy of 3 months old who came to our hospital presented with feeding difficulties, repeated respiratory infections, convulsions for 3 months. He was subsequently diagnosed as cerebral atrophy, and growth retardation. All exons were sequenced.c.211G>A(p.A71T, maternal), c.436T>A(p.F146I, paternal) were detected. After treatment of coenzyme Q10, the convulsive symptoms improved significantly. Literature review revealed that totally 14 cases with primary coenzyme Q10 deficiency caused by COQ4 gene mutation were repoted. The onset age varies from neonatal to 18 years old, and the clinical manifestations are heterogeneous, including cardiomyopathy, epilepsy, ataxia, cerebellar atrophy, respiratory insufficiency, and growth retardation. Conclusion For cases with atypical clinical manifestations of primary coenzyme Q10 deficiency, gene detection is helpful for an early diagnosis and treatment.

Identification of a novel splicing mutation in COL1A1 gene in a Chinese family affected with typeⅠosteogenesis imperfecta / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic cause for a large family affected with typeⅠosteogenesis imperfecta.</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral venous blood samples. The entire coding region and intron-exon boundaries of the COL1A1 gene were subjected to PCR amplification and direct sequencing. Total RNA was also extracted from immortalized B cell lines from the patients, with the first strand of cDNA synthesized with an oligo(dT)18 primer. The PCR products were directly sequenced using the TA cloned plasmid.</p><p><b>RESULTS</b>A c.3208G>A mutation has been identified in the COL1A1 gene, which can alter the splicing pattern of mRNA.</p><p><b>CONCLUSION</b>A novel splicing mutation c.3208G>A of the COL1A1 gene probably underlies the disease.</p>