Genetic analysis and prenatal diagnosis of a child with Multiple congenital malformations-hypotonia-epilepsy syndrome type 3 due to variants of PIGT gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic etiology of a child with Multiple congenital malformations-hypotonia-epilepsy syndrome type 3 (MCAHS3) and provide prenatal diagnosis for her parents.@*METHODS@#A female child who had presented at Linyi People's Hospital on 27 July 2022 for recurrent convulsions for over 4 years was selected as the study subject. Clinical data of the child were collected. Peripheral blood samples were taken from the child and her parents and subjected for whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Prenatal diagnosis was carried out on amniotic fluid sample at 18 weeks' gestation. Bioinformatic software was used to analyze the pathogenicity of the protein model for the variant loci.@*RESULTS@#The child was a 4-year-old female with frequent seizures, peculiar facial appearance, hypotonia and severe developmental delay. Genetic analysis revealed that she has harbored compound heterozygous variants of the PIGT gene, namely c.1126del (p.H376Tfs*56) and c.1285G>C (p.E429Q), which were respectively inherited from her mother and father. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.1126del (p.H376Tfs*56) variant was predicted to be pathogenic (PVS1+PM2_Supporting+PM4), and c.1285G>C (p.E429Q) variant was predicted to be likely pathogenic (PM2_Supporting+PM3+PM4). Prenatal diagnosis suggested that the fetus also harbored the same compound heterozygous variants, and the pregnancy was terminated with induced labor.@*CONCLUSION@#The c.1126del (p.H376Tfs*56) and c.1285G>C (p.E429Q) compound heterozygous variants of the PIGT gene probably underlay the MCAHS3 in this patient, and prenatal diagnosis has prevented birth of further affected child in this family.

One case of developmental epileptic encephalopathy caused by NR4A2 gene variation and literature review / 中华神经科杂志

Objective:To analyze the clinical characteristics of a child with developmental epileptic encephalopathy caused by NR4A2 gene mutation, and to summarize the clinical phenotypes and genotypes to improve the clinician′s understanding of this disease. Methods:The clinical data of a child with developmental epileptic encephalopathy admitted to Linyi People′s Hospital in August 2022 were collected, video electroencephalogram, craniocerebral magnetic resonance imaging and family whole exon sequencing were improved, and the suspected mutation sites were verified by Sanger sequencing. Relevant literature was consulted to summarize the clinical phenotypes and genetic characteristics of nervous system diseases caused by NR4A2 gene. Results:It was found that there was a heterozygous missense mutation at the locus c.866G>A (p.A289H) of NR4A2 gene in the child, which was a de novo mutation, and both parents were wild type. According to the American Society of Medical Genetics and Genomics variation classification, it was assessed as a suspected pathogenic variation. Through literature review, there were 16 related cases reported internationally, with clinical phenotypes including mental retardation/mental retardation, language disorders, seizures, muscle tone changes and different psychological and behavioral problems. Conclusions:The NR4A2 gene is not only associated with dopa responsive disorders, but also with neurological development, intellectual impairment, language development delay, and epilepsy. The mutation of NR42A gene c.866G>A (p.A289H) is the genetic cause of the patient, and the detection of this locus expands the NR4A2 gene spectrum. NR4A2 gene is one of the pathogenic genes of developmental epileptic encephalopathy.

Clinical and genetic analysis of a child with hyperekplexia / 中华神经科杂志

Objective:To analyze the clinical phenotype and gene sequencing results of a child with hyperekplexia, and to clarify her genetic etiology.Methods:The clinical information of the child was collected, and the whole exome sequencing of the child and her parents was performed. The suspected pathogenic variants were verified by Sanger sequencing and bioinformatics analysis.Results:There was a 12 years old girl, who was hospitalized in the Department of Pediatric Neurology of Linyi People′s Hospital because of "paroxysmal limb stiffness for more than 11 years and aggravated for half a month" on July 4, 2022. The girl showed exaggerated startle reflexes and generalized siffness in response to external sudden, unexpected stimuli, occasionally accompanied by apnea and cyanosis, frequent attacks occurred several times a day, lasting for 1-30 minutes, and early head and abdomen flexion can be relieved. She showed normal growth and development, no abnormality in brain magnetic resonance imaging and video electroencephalogram during seizure. The whole exome sequencing showed that there was a missense heterozygous mutation c.643T>C(p.W215R) in the SLC6A5 gene of the child. Neither of the parents carried this mutation, which was a novel and de novo variant. According to the guidelines of American College of Medical Genetics and Genomics, this variant was a likely pathogenic variant [PS2: de novo (both maternity and paternity confirmed) in the patient with the disease and no family history; PM2: undetected variants in the normal population; PP3: multiple softwares predicted that this mutation would have harmful effects on genes or gene products], and highly conserved. Swiss modeling found that the hydrogen bond of the modified amino acid also changed. Conclusions:Hyperekplexia is relatively rare and prone to misdiagnosis. The main clinical features are excessive startle reflexes (limb shaking, or jumping) to unexpected external stimuli, resulting in overall stiffness, normal growth and development, and normal video electroencephalogram during the seizure. The likely pathogenic heterozygous missense variant c.643T>C (p.W215R) of SLC6A5 gene is the genetic cause of this case.

Clinical features of mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes syndrome in twin brothers / 临床儿科杂志

Objective To explore the clinical features of mitochondrial encephalomyopathy lactic acidosis and strokelike episodes (MELAS) syndrome in fratemal twins brothers.Methods The clinical data,the results of laboratory examinations,electroencephalogram (EEG),imaging,and gene detection,and the process of diagnosis and treatment were retrospectively analyzed the fraternal twin brothers with MELAS syndrome.Results The proband,a 7-year-old male,had intermittent headaches,vomit and twitching at onset.He suffered from exercise intolerance,fatigue,accompanied by short stature and hairy.The fasting blood lactic acid level was increased.Multiple video EEG showed the slowdown of background activity.Head MRI showed recurrent lesions with the characteristics of migration and variation.The point mutation rate of mtDNA A3243G was 34.7％.The diagnosis of MELAS was confirmed.At the same time,his fraternal twin brother was screened and found that his point mutation rate of A3243G was 30.0％.Although there was no clinical symptom at that time,he was onset with convulsion after 3 years.Conclusions Gene detection and family screening are helpful for the early diagnosis of MELAS.The mutation rate of A3243G is very high,which can cause an early onset and serious clinical symptoms.