Prenatal diagnosis and genetic analysis of a special case with complex structural rearrangements of chromosome 8 / 中华医学遗传学杂志

OBJECTIVE@#To present on a prenatally diagnosed case with complex structural rearrangements of chromosome 8.@*METHODS@#Chromosome karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) were carried out for a fetus with increased nuchal thickness.@*RESULTS@#The karyotype of the amniotic fluid sample showed extra materials on 8p. FISH revealed a centromeric signal at the terminal of 8p with absence of telomeric signal. CMA revealed partial deletion of 8p23.3 [(208049_2256732)×1], partial duplication of 8p23.3p23.2 [(2259519_3016818)×3], and partial duplication of 8q [8q11.1q12.2(45951900_60989083)×3].@*CONCLUSION@#The complex structural rearrangements of chromosome 8 in this case has differed from the commonly seen inv dup del(8p).

Genetic analysis of a fetus with mosaicism of 13q inversion duplication / 中华医学遗传学杂志

OBJECTIVE@#To report on a case of mosaicism 13q inversion duplication, analyze its mechanism, and discuss the correlation between its genotype and phenotype.@*METHODS@#Amniotic fluid and umbilical cord blood were collected at 23 and 32 weeks of gestation, respectively. Combined with G-banding chromosome karyotyping analysis, single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) were used to confirm the result.@*RESULTS@#The karyotype of the fetus was determined as 47,XY,+inv dup(13)(q14.3q34)/46,XY. After careful counseling, the couple decided to continue with the pregnancy, and had given birth to a boy at 40 weeks' gestation. Except for a red plaque (hemangioma) on the nose bridge, no obvious abnormality (intelligence to be evaluated) was discovered.@*CONCLUSION@#To provide reference for clinical genetic counseling and risk assessment, the location and proportion of new centromere formation should be fully considered in the case of mosaicism 13q inversion duplication.

Genetic analysis of a 45,X male fetus / 中华医学遗传学杂志

OBJECTIVE@#To analyze the prenatal diagnosis procedure for a 45,X male fetus.@*METHODS@#A 31-year-old women underwent amniocentesis due to a moderate risk of trisomy 21. The fetal cells were subjected to chromosomal karyotyping, BACs-on-Beads (BoBs) assay, chromosomal microarray analysis and fluorescence in situ hybridization.@*RESULTS@#Combined analyses revealed that the whole of Yp has translocated to 21p, which yielded a fetal karyotype of 45,X,dic(Y;21)(q11;p11).ishdic(Y;21)(SRY+,CEPY+;CEP21+).@*CONCLUSION@#BoBs and modified N-banding method are helpful for the diagnosis of 45,X male fetus with Yp translocation.

Optimization of chromosome flaking technique for mesenchymal stem cells / 中华医学遗传学杂志

OBJECTIVE@#To optimize the condition for chromosome flaking of mesenchymal stem cells to ensure the cytogenetic quality control of expanding production and clinical application.@*METHODS@#Chromosomal flaking methods were optimized from current chromosome preparation techniques from the aspects of MSCs cell culture concentration, colchicine treatment time and low permeability time.@*RESULTS@#By repeated pre-experiments, the optimal MSCS chromosome flaking condition of MSCs was determined as cell culture concentration of (1-2)× 10 cells per T25 cell culture bottle, and the colchicines processing time was determined as 2 hours and 10 minutes, and the low permeability was 1 hour.@*CONCLUSION@#The optimized chromosome flaking condition can fulfill the requirement of cytogenetic quality control for MSCs.

Genetic analysis of three families affected with split-hand/split-foot malformation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic etiology of three families affected with split-hand/split-foot malformation (SHFM).</p><p><b>METHODS</b>Peripheral venous blood samples from 21 members of pedigree 1, 2 members of pedigree 2, and 2 members of pedigree 3 were collected. PCR-Sanger sequencing, microarray chip, fluorescence in situ hybridization (FISH), real-time PCR, and next-generation sequencing were employed to screen the mutations in the 3 families. The effect of the identified mutations on the finger (toe) abnormality were also explored.</p><p><b>RESULTS</b>Microarray and real-time PCR analysis has identified a duplication in all patients from pedigrees 1 and 3, which have spanned FKSG40, TLX1, LBX1, BTRC, POLL and FBXW4 (exons 6-9) and LBX1, BTRC, POLL and FBXW4 (exons 6-9) genes, respectively. A missense mutation of the TP63 gene, namely c.692A>G (p.Tyr231Cys), was found in two patients from pedigree 2. FISH analysis of chromosome 10 showed that the rearrangement could fita tandem duplication model. However, next-generation sequencing did not identify the breakpoint.</p><p><b>CONCLUSION</b>The genetic etiology for three families affected with SHFM have been identified, which has provideda basis for genetic counseling and guidance for reproduction.</p>