Basic Sciences of Medicine 2012, 1(5): 40-45
DOI: 10.5923/j.medicine.20120105.04
Molecular Screening of Obesity Candidate Gene Variant
Neuropeptide Y Receptor Type 2 (NPY2R) A172T among
Malaysian Subjects
Yau-Wei Lee
1
, Phee-Phee Chia
2
, Yee-How Say
1,*
1
Department of Biomedical Science, Faculty of Science
2
Department of Science and Engineering, Centre for Foundation Studies, Universiti Tunku Abdul Rahman (UTAR) Perak Campus, 31900,
Kampar, Perak, Malaysia
Abstract The association of the A172T Neuropeptide Y Receptor Type 2 (NPY2R) gene with obesity and metabolic
syndrome has not been widely studied in the Malaysian population. Therefore, the objective of this study was to investigate
the association of NPY2R A172T gene variant with obesity, metabolic syndrome, related anthropometric measurements,
glucose level, blood pressure and the demographic characteristics among Kampar Health Clinic subjects. In total, 168
subjects (68 males, 100 females; 66 obese, 102 non obese; 47 Malay, 89 Chinese, 32 Indians) were recruited in this study via
convenience sampling and anthropometric measurements were taken. Genotyping was performed using HaeIII Polymerase
Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) revealing 121 AA, 37 AT and 10 TT subjects;
minor allele frequency 0.170. NPY2R A172T genotypes and alleles did not show any association with obesity (p = 0.982;
0.857, respectively), gender (p = 0.129; 0.245, respectively) and ethnicity (p = 0.581; 0.390, respectively). Besides, they did
not show any association with the presence of metabolic syndrome according to 3 criteria in the modified NCEP ATP III (p =
0.447; 0.288, respectively). In conclusion, the NPY2R A172T gene variant was not associated with obesity, obesity-related
traits and metabolic syndrome among Malaysian subjects in this study.
Keywords Neuropeptide Y Receptor 2, Single Nucleotide Polymorphism, Obesity, Metabolic Syndrome, Anthropometric
Measurements, Malaysia
1. Introduction
Obesity is defined as a state of increased adiposity
resulting from chronic nutrient excess and it has reached its
epidemic levels in modern society. Malaysia is part of this
epidemic too, whereby the prevalence rate of obesity has
increased from 4.4% to 14.0% as reported by the Malaysian
National Health and Morbidity Survey (NHMS) II in 1996
and NHMS III in 2006, respectively[1]. The increased
prevalence of obesity has been accompanied by a parallel
increase in the prevalence of the metabolic syndrome (MetS)
or “syndrome X”[2]. The definition in diagnosing MetS was
first introduced by WHO in 1998 whereby this definition
focused on insulin resistance as a main criterion[3]. In
addition, the National Cholesterol Education Program Adult
Panel Treatment III (NCEP ATP III) and International
Diabetes Foundation (IDF) introduced their own set of
criteria in diagnosing metabolic syndrome in 2001 and 2005,
* Corresponding author:
sayyh@utar.edu.my (Yee-How Say)
Published online at http://journal.sapub.org/medicine
Copyright © 2012 Scientific & Academic Publishing. All Rights Reserved
respectively[4,5]. NCEP ATP III criteria are based on the
presence of 3 out of 5 factors in diagnosing metabolic
syndrome and the risk factors are waist circumference >102
cm in men and >88cm in women, blood pressure, serum
cholesterol, plasma triglycerides and fasting blood
glucose[4]. This definition is rather suitable in the US
population than Asians due to the low prevalence of
metabolic syndrome among Asians[6]. Thus, a modified
version of NCEP-ATP III is made in waist circumference for
Asians; > 80 cm for women and >90 cm in men is used to
define central obesity[7,8].
The neuropeptide Y receptor type 2 (NPY2R) is one of the
class of G-protein coupled receptors activated by closely
related peptide hormones - neuropeptide Y (NPY), peptide
YY (PYY) and pancreatic polypeptide[9]. NPY2R has a
heptahelix structure which comprises glycosylation site at
the amino-terminal, two extracellular cysteines which form a
disulfide bridge and a cysteine molecule at the cytoplasmic
tail of the N-linked carbohydrate[10]. It binds selectively to
Y2 receptor subtype agonists such as NPY
3-36
and
PYY
3-36[
11]. The gene encoding for it, NPY2R, is located on
chromosome 4q32.1 which consists 8447 kilobases
including 2 exons and the coding region is located on the