Background: The HLA-B*15:02 polymorphism in epileptic patients is known to be associated with carbamazepine-induced Stevens-Johnson syndrome (SJS). The prevalence of HLA-B*15:02 polymorphism seemed to be ethnic-specific with a higher frequency of HLA-B*15:02 in Asian compared to the Europeans. This study was performed to determine the frequency of the HLA-B*15:02 polymorphism in epileptic patients at the Chancellor Tuanku Muhriz Hospital-UKM Medical Centre (HCTM-UKMMC) using high resolution melting-real time PCR (HRM-QPCR) method.
Methods: We performed a fast and effective in-house high resolution melting-real time polymerase chain reaction method and compared it with the conventional multiplex-PCR method. The specificity and sensitivity of each test were also determined using DNA from saliva.
Results: Using the conventional multiplexPCR approach for screening, 25 out of 64 (39.1%) epileptic patients were positive for HLA-B*15:02. However, using the HRM-QPCR technique, 24/64 (37.5%) of the patients were positive. The one patient who tested positive by the multiplex-PCR but negative using the HRM-QPCR turned out to be negative by DNA sequencing. The HRM-QPCR and DNA sequencing showed 100% sensitivity and specificity. The multiplex-PCR showed 100% sensitivity and 98.4% specificity compared to both HRM-QPCR and DNA sequencing. The HRM-QPCR is also more cost-effective (
VACTERL association is a rare genetic disorder involving at least three of the following congenital
malformations: vertebral defects (V), anal atresia (A), cardiac defects (C), trachea-oesophageal fistula with
or without oesophageal atresia (TE), renal anomalies (R) and limb abnormalities (L). Until now, the
aetiology of VACTERL association is unknown, particularly at the molecular level. Here, we performed
whole exome sequencing (WES) of an infant with VACTERL association. The patient was delivered
prematurely at 30 weeks and had 4/6 of the VACTERL malformations. Trio-WES analysis was performed
using Torrent Suite and ANNOVAR. Polymorphisms with an allele frequency of >0.01 were excluded, and
the remaining variants were filtered based on de novo mutations, autosomal recessive, X-linked and di-genic
inheritance traits. In this patient, no homozygous, compound heterozygous or X-linked mutations was
associated with VACTERL. However, we identified two heterozygous mutations; KIF27
(ENST00000297814: c.3004A> C:p.N1002H) and GNAS (ENST00000371098: c.205C>A:p.H69N) genes that
were inherited from her father and mother respectively. A de novo, IFT140 gene mutation
(ENST00000426508: c.683C>G:p.S228C) was also identified in this patient. The VACTERL phenotype in
this patient may due to heterozygous mutations affecting KIF27 and GNAS genes, inherited via autosomal
recessive trait. In addition, the IFT140 gene mutation may also be involved. These genes are known to be
directly or non-directly involved in the sonic hedgehog signalling that is known to be implicated in
VACTERL. This is the first report of these genetic mutations in association with VACTERL.