ABSTRACT
Objective To understand the correlation between chromosome deletion and the phenotypes in cases of ring chromosome 6 syndrome.Methods Two cases of ring chromosome 6 syndrome persented to the Peking University First Hospital in 2013 were studied.Case 1 was a fetus diagnosed as having ring chromosome 6 with karyotype 46,XY,r (6) [14]/46,XY,r (6; 6) [1]/45,XY,-6[15] from a pregnant woman who received prenatal examination because of high risk found in serum screening for Down's syndrome at 21 +1 weeks of gestation.Case 2 was an eight-month-old female infant with growth retardation and congenital facial anomaly,whose karyotype was 46,XX,r (6) /47,XX,r (6) × 2/46,XX,r (6; 6) /45,XX,-6.Multiplex ligation-dependent probe amplification and array-based comparative genomic hybridization were used to detect the location of chromosome telomeric loss and its size,and the correlation between chromosome deletion and the phenotypes was analyzed by reviewing related literatures.Results Case 1 was confirmed to have short-arm terminal deletions on 6p25.3-25.2 (2.42 Mb) which mainly included DUSP22,IRF4,EXOC2,FOXC1,FOXF2 and FOXQ genes,and long-arm terminal deletions on 6q26-27 (7.84 Mb) mainly included PARK2,PACRG,LOC28596 and RPS6KA2 genes.Case 2 had short-arm terminal deletions on 6p25.3-25.1 (5.44 Mb) which included DUSP22,IRF4,EXOC2,FOXC1,FOXF2,FOXQ and SERPINB6 genes,and long-arm terminal deletions on 6q27 (0.16 Mb) which included PSMB1,TBP and PDCD2 genes.Except for the growth retardation,the common feature of ring syndrome,in both cases,cerebellum hypoplasia was observed in case 1,and microcephaly and esotropia were observed in case 2.Conclusions The difference of phenotypes in patients with a ring chromosome 6 is closely associated with the location and size of the deletion in chromosome 6.
ABSTRACT
Deletions of chromosome 6q, particularly in the proximal region, are relatively rare. Here, we report on a de novo interstitial deletion of (6)(q13q16.2) in a girl with facial dysmorphism, congenital hip dislocation, porencephaly, and brain atrophy. Array comparative genomic hybridization analysis showed arr 6q13q16.2(73,378,824-99,824,130), demonstrating higher resolution than the conventional cytogenetic findings, del(6)(q12q15). The clinical data were analyzed and compared with those of similar patients previously reported in the literature.
Subject(s)
Female , Humans , Infant, Newborn , Abnormalities, Multiple/genetics , Chromosome Deletion , Chromosomes, Human, Pair 6 , Comparative Genomic Hybridization/methods , Karyotyping , Oligonucleotide Array Sequence AnalysisABSTRACT
Objective To elucidate the genetic base of psoriasis for Chinese patients, the positional candidate loci (D6S273?D6S276?D6S422?D6S299?D6S291?D4S1535?D4S1652?D4S171)previously reported in the regions 6p21.3 and 4q were studied in some carefully examined psoriatic families in order to establish whether the eight reported microsatellites loci(STRs) underlay susceptibility to psoriasis in different populations. Methods Two hundred and five probands with psoriasis vulgaris were identified from outpatients attending the Institute of Dermatology, Chinese Academy of Medical Sciences. Genotypes were generated at 8 polymorphic loci on chromosome 6p21 and 4q in 14 pedigrees. The results were analyzed parametrically by linkage 5.0 software. Results There was evidence for linkage to D6S273 in 6p21.3 (the LOD score was 1.26) . No evidence for linkage was obtained at other loci including three loci on chromosome 4q. Conclusions This study confirms the presence of a psoriasis susceptibility locus on chromosome 6p previously studied. It is shown that there may be psoriasis susceptibility locus D6S273 on chromosome 6p21.3 in the Chinese population.