Clinical, molecular genetic analysis, and treatment of 3 children with sitosterolemia / 中华儿科杂志

Objective@#To investigate clinical, molecular genetic characteristics, and treatment outcomes of 3 children with sitosterolemia.@*Methods@#Three cases of children presented with multiple xanthomas during June 2016 to June 2017 were included. The clinical manifestations, laboratory examinations and follow-up data were retrospectively analyzed. DNA was extracted from peripheral blood and analyzed with whole exome sequencing(WES). All the detected variants were confirmed by Sanger sequencing. Plasma plant sterol concentrations were measured by gas chromatography-mass spectrometry.@*Results@#Three cases of children including 1 boy and 2 girls presented with multiple linear and intertriginous xanthomas around skin of the joint areas at the age from 15 months to 6 years and 2 months. Total cholesterol of the 3 cases was elevated to 14.45, 15.47 and 15.85 mmol/L (3.36-6.46), and low density lipoprotein cholesterol was 9.02, 13.54 and 12.47 mmol/L (< 3.36) respectively. Genetic analysis with WES revealed that 2 cases carried compound heterozygous variants in ABCG5 gene, 1 case carried compound heterozygous variants in ABCG8 gene. Two reported variants (p. N437K, p.R446X) and one novel variant (p.Q251X) of ABCG5 were identified in case 2 and 3. Two novel ABCG8 variants (p.R263Q, c.1528_1530delATC) were found in case 1. All these children had extremely high plasma plant sterol levels, thus the diagnosis of sitosterolemia was confirming. The campesterol level was 111.35, 102.86 and 58.91 μmol/L(0.01-10.00), the stigmasterol was 14.97, 29.43 and 17.79 μmol/L (0.10-8.50) and the sitosterol was 231.20, 177.66 and 114.20 μmol/L (1.00-15.00) respectively. The total serum cholesterol levels of three children decreased to nomal after the patients were placed on the low plant sterol/low cholesterol diet. The xanthomas regressed gradually, and almost disappeared after 8 months of treatment in case 1 and 3.@*Conclusions@#Children with sitosterolemia presented with skin xanthomas around the joint areas. The level of total cholesterol, low density lipoprotein cholesterol and plant sterols increased obviously. One novel variant (p.Q251X) of ABCG5 and 2 novel variants (p.R263Q, c.1528_1530delATC) of ABCG8 were identified. Children with sitosterolemia responded well to a low plant sterols/low cholesterol diet.

Clinical phenotypes and genetic study of 2 cases with 22q13 deletion syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the genetic etiology and clinical characteristics of 2 boys featuring development delay (DD).</p><p><b>METHODS</b>Routine chromosomal banding was performed to analyze the karyotypes of the patients and their parents. Single nucleotide polymorphism array (SNP array) analysis was employed to identify pathogenic deletion/duplication of chromosomes, and quantitative real-time PCR (qPCR) was performed to confirm the results.</p><p><b>RESULTS</b>Patient 1 showed a global developmental delay, especially impaired language development, seizures, behavioral problems belonging to the autism spectrum and mild facial dysmorphism. Patient 2 mainly presented with severely delayed speech and moderate intellectual disability, but did not have obvious facial dysmorphism and autistic-like behavior. The diagnosis of 22q13 syndrome was established based on identification of a heterozygous microdeletion at chromosome 22q13.33 in both patients (69 kb and 587 kb, respectively) by the SNP array analysis. Both patients had deletions of SHANK3 and ACR, which are located at the end of 22q. Quantitative real-time PCR verified that the deletion of SHANK3 gene in both patients were de novo in origin.</p><p><b>CONCLUSION</b>Two cases of 22q13 deletion syndrome have been diagnosed by SNP array analysis. Deletion of SHANK3 gene may be the major contributor to the clinical manifestations of the patients. SNP array analysis can facilitate discovery of microdeletions, which has played an important role in the diagnosis and genetic counseling for the family.</p>

Diagnostic follow-up for a case of mosaic trisomy 22 by non-invasive prenatal testing / 中华检验医学杂志

Objective To estimate prenatal diagnoses strategy with abnormal results of non-invasive prenatal testing (NIPT) based on a case of mosaic for trisomy 22.Methods The pregnanct woman was recruited from Department of Prenatal Diagnosis Center of Xinhua Hospital.Ultrasound scans suggested fetal nuchal translucency was 3.5 mm.Peripheral venous blood was drawn from the pregnant woman for NIPT at 12+2 weeks gestation.For further prenatal diagnosis, amniocentesis was conducted at 16+2 weeks gestation, and karyotype analysis combination with chromosome microarray analysis (CMA) was executed to analysis amniocytes.Results NIPT results suggested that chromosome 21, 18 and 13 were normal and supplementary reports suggested that chromosome 22 were slightly above the normal range.Karyotype analyzed 35 cultured cells.Each of them revealed a normal female karyotype.However, CMA results suggested that chromosome 22 gain mosaic and its copy number was 2.26.The fetus was diagnosed as high possibility of mosaic for trisomy 22.Conclusions Combined with the NIPT results, which was slightly gain mosaic of chromosome 22, a prenatal diagnosis strategy were proposed.When NIPT results suggest chromosomal abnormities, karyotype analysis combination with CMA to diagnose were recommended.

Influence of parental origins to the interpretation of chromosomal microarray based clinical pathogenicity analysis / 中华检验医学杂志

Objective To analyze the influence of validating the parental origin to the interpretation of clinical pathogenicity of total 54 copy number variations(CNV)with different clinical significance in 46 patients undergo chromosomal microarray analysis(CMA).Methods A retrospective study.This study enrolled 46 patients conducted in Department of Pediatric Endocrinology and Genetics of Shanghai Xinhua Hospital during the period of August 2014 to December 2015,involving 54 different CNVs detected by CMA.The parental origin of CNVs was examined by CMA or quantitative real-time polymerase chain reaction.Results Totally 54 different CNVs were found in 46 patients by CMA.Seventeen out of the 54 CNVs were pathogenic variations.After validating the parental origin,14 CNVs were proved de novo mutation,while 3 CNVs have maternal origin including 1q21.1 deletion syndrome,Xq27.3q28 and Xq22.1q22.3 duplications which inherited from maternal X chromosome.CNVs of 1q21.1 deletion syndrome often inherited from parents,and no phenotype appears on mother which may be due to the deactivation mechanism of duplications on mother′s X chromosome.Therefore,these 17 pathogenic variations were still considered to be clinical pathogenic significance after validating the parental origin.Ten out of 54 CNVs were variants of uncertain significance-likely pathogenic.After parental original validation,3 CNVs were proved de novo mutation considering likely pathogenic significance,while 7 CNVs have parental origin still judged to be unknown clinical pathogenicity.Twenty-seven out of 54 CNVs were variants of uncertain significance.After validating the parental origin,only 1 CNV was proved de novo mutation considering likely pathogenic significance,while all the others had parental origin considered to be variations likely benign.Conclusion CNVs reported as likely pathogenic should be validated the parental origin in order to further study their clinical pathogenicity,while variants of uncertain significance can preliminary clear its nature by validating parental origin.