8q23-q24 duplication--further delineation of a rare chromosomal abnormality.
ABSTRACT Presented here is a young girl with a rare interstitial duplication of 8q23.3-q24.21. At birth, unusual facial features led to karyotype analysis with a finding of increased material in 8q. Specific determination of where the extra material came from required comparative genomic hybridization (CGH). The affected girl has dysmorphic facial features including hypertelorism, a wide nasal bridge, retrognathia, hyperopic astigmatism, hirsutism, and developmental delay. The area duplicated includes at least 47 genes including TRPS1 and EXT1. Her features will be described and compared to two similar cases.
American Journal of Medical Genetics Part A 09/2013; 161(9). DOI:10.1002/ajmg.a.36039 · 2.05 Impact Factor
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ABSTRACT: We present a rare case of 8q interstitial duplication derived from maternal balanced translocations in a patient with bilateral cleft lip and palate in syndromic form associated with other congenital malformations. G-banding cytogenetic analysis revealed a chromosomal abnormality in the form of the karyotype 46,XX der(22)t(8;22)(q22.1;p11.1)mat. Chromosome microarray analysis evidenced a 49 Mb duplicated segment of chromosome 8q with no pathogenic imbalances on chromosome 22. Two siblings also carry the balanced translocation. We have compared this case with other "pure" trisomies of 8q patients reported in the literature and with genome wide association studies recently published. This work highlights the involvement of chromosome 8q in orofacial clefts.01/2014; 2014:730375. DOI:10.1155/2014/730375
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ABSTRACT: Copy-number variants (CNVs) represent a significant interpretative challenge, given that each CNV typically affects the dosage of multiple genes. Here we report on five individuals with coloboma, microcephaly, developmental delay, short stature, and craniofacial, cardiac, and renal defects who harbor overlapping microdeletions on 8q23.4. Fine mapping localized a commonly deleted 78 kb region that contains three genes: SCRIB, NRBP2, and PUF60. In vivo dissection of the CNV showed discrete contributions of the planar cell polarity effector SCRIB and the splicing factor PUF60 to the syndromic phenotype, and the combinatorial suppression of both genes exacerbated some, but not all, phenotypic components. Consistent with these findings, we identified an individual with microcephaly, short stature, intellectual disability, and heart defects with a de novo c.505C>T variant leading to a p.His169Tyr change in PUF60. Functional testing of this allele in vivo and in vitro showed that the mutation perturbs the relative dosage of two PUF60 isoforms and, subsequently, the splicing efficiency of downstream PUF60 targets. These data inform the functions of two genes not associated previously with human genetic disease and demonstrate how CNVs can exhibit complex genetic architecture, with the phenotype being the amalgam of both discrete dosage dysfunction of single transcripts and also of binary genetic interactions.The American Journal of Human Genetics 10/2013; DOI:10.1016/j.ajhg.2013.09.010 · 10.99 Impact Factor