Phenotypic and genetic analysis of an inv dup(15) case with a BP3:BP3 rearrangement / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a case of supernumerary marker chromosome (SMC) with combined genetic techniques and explore its correlation with the clinical phenotype.</p><p><b>METHODS</b>The SMC was analyzed with G-banded karyotyping, multiplex ligation dependent probe amplification (MLPA), fluorescence in situ hybridization (FISH), and single nucleotide polymorphism array (SNP-array).</p><p><b>RESULTS</b>G-banding analysis indicated that the patient has a karyotype of 47,XX,+mar. MLPA showed that there were duplications of proximal 15q. FISH assay using D15Z4 probes indicated that the SMC was a pseudodicentric chromosome derived from chromosome 15. And SNP-array revealed that there were two extra copies of 15q11-13 region spanning from locus 20 161 372 to 29 071 810.</p><p><b>CONCLUSION</b>The duplication of Prader-Willi/Angelman syndrome critical region probably underlies the abnormal phenotype of the inv dup(15) case with a BP3:BP3 rearrangement.</p>

Nursing of patients with toxic epidermal necrolysis / 现代临床护理

Objective To summarize the main nursing points of toxic epidermal necrolysis. Methods On the foundation of conventional therapy, an overall assessment was carried out among 10 patients with toxic epidermal necrolysis. On loose skin with erythema, a combination of zinc oxide and talcum powder was externally applied to skin lesions where blisters were not broken in order to promote dry-style exfoliation of the skin lesion. After infrared irradiation, gauze containing MEBO was applied externally to skin lesions with eroded secretions to moisturize them, thus facilitating healing of the skin lesion. Meanwhile, mucosa of special part of patient's body was well nursed. Protective isolation was enhanced in order to reduce secondary infection. The patient's conditions were observed closely. Diet guidance was also done. Results All the patients were dry-style exfoliated with treatment ranges reaching up to 30%to 60%of the affected area. Dry-style exfoliation time was between 5 to 10 days, with an average of 7.20 ±1.69 days. The area of skin lesion erosion ranged from 10% to 60%. Following the external application of MEBO gauze to moisturize and heal, skin lesion healing time ranged from 7 to 18 days with an average of 13.70 ±3.40 days. Conclusion According to the specific situation of toxic epidermal necrolysis, targeted nursing and treatment can promote the dry-style exfoliation of skin lesions, reduce the area of skin erosions, alleviate the suffering of patients and promote healing of the skin lesion.

Cytogenetic and molecular genetic analysis of a case with mosaic marker chromosomes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the source of small supernumerary marker chromosome in a case.</p><p><b>METHODS</b>G-banded karyotyping, fluorescence in situ hybridization, multiple sequence tagged sites (STS) of the Y chromosome, and Illumima Human Cyto SNP-12 Beadchip analysis were carried out.</p><p><b>RESULTS</b>The karyotype was mos 46,X,+mar1[21]/46,X,+mar2[78]. Y chromosome STS analysis has displayed the presence of sy84, sY86, USP9Y and DDX3Y genes from the AZFa region, and sY1227 of the AZFb region, while sY1228, sY1015, sY127, sY134 from the AZFb region, and sY254 and sY255 from the AZFc region were missing. FISH analysis has verified both of the marker chromosomes to be Y chromosome fragments. Mar1 was ish.idic(Y)(q11.2)(SRY++,DXZ1+,DYZ3++,DYZ1-), while mar2 was ish.del(Y)(q11.2)(SRY+,DXZ1+,DYZ3+,DYZ1-). Single nucleotide polymorphism (SNP) microarray analysis showed that the Yq11.2-Yq12 has lost a 10.81 Mb fragment.</p><p><b>CONCLUSION</b>The marker chromosomes were verified to be aberrant Y chromosomes, with the breakage and recombination occurring in Yq11.2. Mar 1 was an isodicentric Y chromosome (idic(Y)pter to q11.2::q11.2 to pter), and mar2 was del(Y)(q11.2). The karyotype was mos 46,X,ish idic(Y)(q11.2)(DYZ3++,SRY++,DXZ1+,DYZ1-)[21]/46,X,ish del(Y)(q11.2)(DYZ3+,SRY+,DXZ1+,DYZ1-)[78]. Combined FISH, Y chromosome STS analysis, SNP microarray analysis and other technologies can facilitate determination of the nature of marker chromosomes.</p>

Genetic diagnosis and analysis of related genes for a pedigree with 2p25 and 12p13 cryptic rearrangements / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze chromosome aberration in a child with mental retardation and abnormalities and its parents.</p><p><b>METHODS</b>Chromosome G banding, multiplex ligation-dependent probe amplification, fluorescence in situ hybridization and single nucleotide polymorphisms array were employed for analysis.</p><p><b>RESULTS</b>Karyotype analysis revealed that the child was 46,XX and the father was 46,XY, while the mother was 46,XX, add (12)(p13). Subtelomeric region analysis with MLPA displayed that the child has reduced ACP1 gene copy number in 2p25 region and increased SLC6A12,KDM5A gene copy numbers in 12p11 region. SNP-array has fine mapped the duplication to 12p13.33-p12.3, a 15.142 Mb region, and a deletion to 2p25.3 for 3.194 Mb, which resulted in duplication of 9 genes including SLC6A12 as well as deletion of 11 genes including SNTG2, respectively. FISH analysis revealed that the child was 46,XX,ish,der(2),t(2;12)(p25;p13)mat, or partial monosomy 2p25 and partial trisomy 12p13. In addition,the mother was a carrier with cryptic balanced translocation chromosome, 46,XX,isht(2;12) (p25;p13). Mental abnormalities and retardation of the child may be attributed to heterozygous deletion of SNTG2, MYT1L genes and duplication of SLC6A12 gene.</p><p><b>CONCLUSION</b>Combined use of MLPA, FISH and SNP-array can facilitate accurate diagnosis of cryptic rearrangement at genomic level.</p>

Analysis of APC gene mutation in a familial adenomatous polyposis pedigree / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze mutation of adenomatous polyposis coli (APC) gene in a family affected with familial adenomatous polyposis.</p><p><b>METHODS</b>The diagnosis was made based on clinical manifestations, family history, presence of numerous polyps in the colon as well as pathological examination. Peripheral blood samples were collected, and genomic DNA was extracted. Potential mutation of the APC gene was detected by polymerase chain reaction (PCR) and DNA sequencing. After finding the mutation in the proband, the same mutation was screened among other family members. The mutation was also confirmed with PCR-restriction fragment length polymorphism (RFLP), with which 100 unrelated healthy controls were examined.</p><p><b>RESULTS</b>A novel heterozygous nonsense mutation c.2891T>G (L964X) of the APC gene was identified in this pedigree. The mutation has led to premature termination of translation. The same mutation was not detected among the 100 healthy controls.</p><p><b>CONCLUSION</b>The c.2891T>G (L964X) of the APC gene probably underlies the familial adenomatous polyposis in this pedigree. The combined DNA sequencing and PCR-RFLP method is efficient and accurate for the diagnosis.</p>

Subtle mutation analysis of survival motor neuron gene in families with spinal muscular atrophy / 中华检验医学杂志

ObjectiveTo establish a analytical system for the survival motor neuron (SMN) subtle mutation,and evaluate its application in two families with spinal muscular atrophy (SMA).MethodsSMN genes in seven family members from two SMA families were analyzed at both transcript level and genomic level,by the use of the conventional PCR-RFLP,allele-specific PCR,multiplex ligation-dependent probe amplification (MLPA) and T subcloning and sequencing of SMNI gene.ResultsIn family A,the patient had a single SMN1 copy who was carrying nonsense mutation L228X,which was also found in his father.In family B,as the patient's sample was unavailable,the father was indeed a carrier with one normal SMN1 allele and the other SMN1 allele carrying a frameshift mutation 22_23insA.The remaining family members were SMA carriers with one SMN1 copy.ConclusionThis analytical system for SMN subtle mutation offers viable molecular basis for genetic counseling and prenatal diagnosis in SMA families.