B R DuPont

Publications (3)11.03 Total impact

• Article: Disruption of the IL1RAPL1 gene associated with a pericentromeric inversion of the X chromosome in a patient with mental retardation and autism.

  S S Bhat, S Ladd, F Grass, J E Spence, C K Brasington, R J Simensen, C E Schwartz, B R Dupont, R E Stevenson, A K Srivastava
  Clinical Genetics 02/2008; 73(1):94-6. · 3.13 Impact Factor
• Article: Disruption of DMD and deletion of ACSL4 causing developmental delay, hypotonia, and multiple congenital anomalies.

  S S Bhat, K R Schmidt, S Ladd, K C Kim, C E Schwartz, R J Simensen, B R DuPont, R E Stevenson, A K Srivastava
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  ABSTRACT: We have studied a male patient with significant developmental delay, growth failure, hypotonia, girdle weakness, microcephaly, and multiple congenital anomalies including atrial (ASD) and ventricular (VSD) septal defects. Detailed cytogenetic and molecular analyses revealed three de novo X chromosome aberrations and a karyotype 46,Y,der(X)inv(X) (p11.4q11.2)inv(X)(q11.2q21.32 approximately q22.2)del(X)(q22.3q22.3) was determined. The three X chromosome aberrations in the patient include: a pericentric inversion (inv 1) that disrupted the Duchenne muscular dystrophy (DMD) gene, dystrophin, at Xp11.4; an Xq11.2q21.32 approximately q22.2 paracentric inversion (inv 2) putatively affecting no genes; and an interstitial deletion at Xq22.3 that results in functional nullisomy of several known genes, including a gene previously associated with X-linked nonsyndromic mental retardation, acyl-CoA synthetase long chain family member 4 (ACSL4). These findings suggest that the disruption of DMD and the absence of ACSL4 in the patient are responsible for neuromuscular disease and cognitive impairment.
  Cytogenetic and Genome Research 02/2006; 112(1-2):170-5. · 1.53 Impact Factor
• Article: Sorting nexin 3 (SNX3) is disrupted in a patient with a translocation t(6;13)(q21;q12) and microcephaly, microphthalmia, ectrodactyly, prognathism (MMEP) phenotype.

  V S Vervoort, D Viljoen, R Smart, G Suthers, B R DuPont, A Abbott, C E Schwartz
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  ABSTRACT: A patient with microcephaly, microphthalmia, ectrodactyly, and prognathism (MMEP) and mental retardation was previously reported to carry a de novo reciprocal t(6;13)(q21;q12) translocation. In an attempt to identify the presumed causative gene, we mapped the translocation breakpoints using fluorescence in situ hybridisation (FISH). Two overlapping genomic clones crossed the breakpoint on the der(6) chromosome, locating the breakpoint region between D6S1594 and D6S1250. Southern blot analysis allowed us to determine that the sorting nexin 3 gene (SNX3) was disrupted. Using Inverse PCR, we were able to amplify and sequence the der(6) breakpoint region, which exhibited homology to a BAC clone that contained marker D13S250. This clone allowed us to amplify and sequence the der(13) breakpoint region and to determine that no additional rearrangement was present at either breakpoint, nor was another gene disrupted on chromosome 13. Therefore, the translocation was balanced and SNX3 is probably the candidate gene for MMEP in the patient. However, mutation screening by dHPLC and Southern blot analysis of another sporadic case with MMEP failed to detect any point mutations or deletions in the SNX3 coding sequence. Considering the possibility of positional effect, another candidate gene in the vicinity of the der(6) chromosome breakpoint may be responsible for MMEP in the original patient or, just as likely, the MMEP phenotype in the two patients results from genetic heterogeneity.
  Journal of Medical Genetics 01/2003; 39(12):893-9. · 6.36 Impact Factor