Paraoxonase-1 192 enzyme polymorphism in non-syndromic ...

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Paraoxonase-1 192 enzyme polymorphism in non-syndromic ...

A Mehmet Journal of Baki Cell Yokeş and Molecular Biology 7(1): 67-74, 2008

Haliç University, Printed in Turkey.

http://jcmb.halic.edu.tr

Paraoxonase-1 192 enzyme polymorphism in non-syndromic

clefting: In patients and parents

Gürsel Turgut 1 , Arzu Özcan 1,* , Ercan Çakmak 1 , Lütfü Baş 1 , Soner Tatlıdede 1 , Oğuz

Öztürk 2 , Bedia Ağaçhan 2 , Ümit Zeybek 2 and Arzu Ergen 2 .

1

Department of Plastic and Reconstructive Surgery, Sisli Etfal Researh and Educational Hospital, Istanbul,

Turkey.

2

Istanbul University, Institute for experimental medicine, Department of Molecular Medicine. Istanbul,

Turkey.

(*author for correspondence; ozcanarzu79@yahoo.com)

Received 20 November 2007; Accepted 19 June 2008

_______________________________________________________________________________________

Abstract

Most orofacial clefts are nonsyndromic, isolated defects, and are classified into two groups: cleft lip (CL)

with or without cleft palate and cleft palate (CP) only. Both are genetically complex traits, the genetic cause

is stil elusive, it is genetically complex and enviromental factors are also responsible for the pathogenesis.

Epithelial transformation to mesenchyme is an important event during the process of palatogenesis. Specifically,

epithelial-mesenchymal transformation is thought to be critical for the disappearance of the seam and

mesenchymal confluence. In palate formation, apoptosis is thought to facilitate adherence, or touching, of

the opposing epithelium to form a seam. Apoptosis is important to sculpt the organelles in the body during

development. We hypothesize that oxidative stress promotes epithelial cell apoptosis during palate formation.

Oxidative stress occurs when the production of reactive oxygen species (ROS), including free radicals,

exceeds the handling capability of intracellular antioxidant enzymes and extracellular antioxidant defenses.

Excessive oxidative stress leads to peroxidative damage to cells, altered cellular function, and pathologic

effects. Paraoxonase (PON) is a serum enzyme that is associated with antioxidant mechanism. We aim to

determine the prevalance of the PON-1 192 polymorphisms in the patients and control groups. All cases

included in this study are from the medical records of the Plastic, Reconstructive and Esthetic Clinic of Sisli

Etfal Research and Training Hospital from August 2004 to January 2006. 50 nonsyndromic CL and CP cases

and parent were analyzed. Blood specimens were collected in tubes containing EDTA, and DNA was prepared

from leucoycte pellet by SDS lysis ammonium acetate extraction and ethanol precipitation. PON-1

genotypes were determined following PCR according to previously published protocols. Paraoxonase activities

was measured according to Furlong et al. (1989). We evaluated the frequencies of polymorphisms of the

PON1-192 gene in nonsyndromic cleft lip and cleft palate patients and in matched control subjects.

Key Words: Cleft lip and palate, paraoxonase gene polymorphism, paraoxonase enzyme activity, reactive

oxygen species, peroxidative damage.

Sendromik olmayan yarık damak ve dudaklı hasta ve ailelerinde paraoksonaz-1 192

enzim polimorfizmi

Özet

Review Article 67

Orofasyal yarıkların büyük çoğunluğu genellikle nonsendromiktir ve iki farklı gruba ayrılabilir: yarık damak

ile birlikte veya olmaksızın yarık dudak ve sadece yarık damak. Her ikisinin de genetik komponentleri oldukça

karmaşıktır, ayrıca çevresel faktörler de palatogenezde etkilidir ve bir genin veya lokusun izole


A 68

Gürsel Turgut et al.

edilmesi oldukça zordur. Özellikle epitelyal- mezenkim transformasyonu damak bütünlüğünün

sağlanmasında kritik bir olaydır. Damak formasyonunda, apoptoz birbirine karşılıklı gelen epitelin düzgün

damak yapısını oluşturmasını sağlamak için yapışmayı ve dokunmayı artırır. Apoptoz, vücutta gelişim

sırasında organelleri şekillendirmek için önemlidir. Damak formasyonunda oksidatif stresin epitelyal apoptoza

neden olabileceğini ileri sürmekteyiz. Reaktif oksijen ürünlerinin üretimi ile ve hücre içi antioksidatif

enzimlerin ve hücre dışı antioksidatif mekanizmaların aşılması ile oksidatif stres meydana gelir. Aşırı oksidatif

stres hücrede peroksidatif hasar oluşturur ve hücre fonksiyonunu değiştirerek patolojik etkilere neden

olur. Paraoksonaz enzimi antioksidatif mekanizmada etkili bir serum enzimidir.

Bu çalışmamızda oksidatif stres ve yarık dudak/damak palatogenezinde ilişkisini ve bu süreçte paraoksonaz

gen polimorfizminin rolünü açıklamayı amaçladık. Bu çalışmaya dahil edilen vakalar Şişli Etfal Eğitim ve

Araştırma Hastanesi Plastik, Rekonstrüktif ve Cerrahi Klinine Ağustos 2004 ile Ocak 2006 arasında

başvuran hastaların tıbbi kayıtlarından alındı. 50 sendromik olmayan yarık dudak ve damaklı hasta ve aileleri

incelendi. Kan örnekleri EDTA’lı tüplere alındıktan sonra DNA, lökositlerin SDA amonyum asetat lizisi

ile ekstraksiyonu ve etanol presipitasyonu ile hazırlandı. PON1 genotipleri daha önce yayınlanmış protokollere

göre PCR uygulamasını takiben belirlendi. Furlong (1989) tarafından uygulanan yönteme göre serumda

Paraoksonaz aktivitesi araştırıldı. Sendromik olmayan yarık dudak ve damaklı hastalarda ve kontrol

gruplarında PON-1 192 gen polimorfizminin sıklığını araştırdık.

Anahtar Sözcükler : Yarık dudak ve damak, paraoksonaz gen polimorfizmi, paraoksonaz enzim aktivitesi,

reaktif oksijen ürünleri, peroksidatif hasar.

___________________________________________________________________________________

Introduction

Orofacial clefts are common birth defects with a

known genetic component to their etiology.

Orofacial clefts are classified as nonsyndromic

(isolated) or syndromic based on the presence of

other congenital abnormalities. Cleft lip and cleft

palate are two of the most common congenital

abnormalities, with a reported incidence of up to

1 in every 1000 live births (Das et al.,1995) Approximately

20–50% of all orofacial clefts are

associated with one of more than 400 described

syndromes(Forester et al., 2004). These syndromes

often have simple Mendelian inheritance

patterns and are thus amenable to gene identification.

Most orofacial clefts are nonsyndromic,

isolated defects, which can be separated into two

different phenotypes: cleft lip (Gorlin, 2001)

(CL) with or without cleft palate (Gorlin, 2001)

and cleft palate (CP) only. Both are genetically

complex traits, the genetic cause is stil elusive, it

is genetically complex and enviromental factors

are also responsible for the pathogenesis. The

molecular events that underlie the formation of

orofacial structures are under the strict control of

an array of genes that includes the fibroblast

growth factors (FGFS), sonic hedgehog (SHH),

bone morphogenetic proteins (BMPs), members of

the transforming growth factor β (TGF-β) superfamily,

and transcription factors such as Dlx,Pitx,

Hox, Gli and T-box families (Stanier et al., 2004).

Studies of orofacial clefting have shown that CL/P

has complex inheritance patterns as evidenced by a

positive family history for clefting in 33% of the

patients, with no clearly recognizable mode of

inheritance, and reduced penetrance (Wyszynski,

2002).

Birth defects are likely to recur in families not

only because of genetic factors but also as a result

of environmental factors (Murray, 2004). Cigarette

smoking during pregnancy, with the attendant hypoxia,

is associated with several adverse reproductive

outcomes. The most recent meta-Analysis on

the effects of smoking indicates a moderately increased

risk of orofacial clefts (Zeiger et al., 2005).

Maternal nutrition during pregnancy also appears

to play an important role. For example, low dietary

intake of B-complex vitamins, lower or excessive


dietary intake of vitamin A are among the factors

that are associated with the increased risk of cleft

formation (Little et al., 2004 and Finnell et al.,

2004). Increased risks from exposures can suggest

metabolic pathways whose disruption might

trigger the development of clefts. Several studies

have shown that folic acid and other B-complex

vitamins might have a beneficial effect on reducing

the risk of orofacial clefts (Mungeri, 2002 and

Botto et al., 2004).

Of particular importance to a complex trait

such as clefts is the study of the likely impact of

both genetic and environmental factors. Several

studies have investigated interactions of a range

of common environmental factors, such as cigarette

smoking, alcohol intake, multivitamin/folic

acid supplementation and the use of medication,

with variant alleles in several genes that include

TGFA, TGFB3, MSX1, BCL3, RARA, MTHFR,

CYP1A1, NAT1, NAT2, GSTT1 and EPHX

(Munger et al., 2004; Zeiger and Beaty, 2004).

Both apoptosis and epithelial mesenchymal

transformation play a major role in development

of palate. Apoptosis is important to sculpt the

organelles in the body during development.In

palate formation, apoptosis is thought to facilitate

adherence, or touching, of the opposing epithelium

to form a seam (Ferguso and Honig, 1984;

Martinez-Alvarez et al., 2000). Both inhibition of

cell death with a caspase inhibitor and acceleration

of cell death with retinoic acid result in cleft

palate in vitro (Cuervo et al., 2002 and Brunet et

al., 1995). Epithelial transformation to mesenchyme

is an important event during the process of

palatogenesis. Especifically, epithelialmesenchymal

transformation is thought to be

critical for the disappearance of the seam and

Paraoxonase-1 192 enzyme polymorphism 69

A

Table 1. Observed frequencies of the 192A and 192B alleles, and the AA, BB, and AB genotypes and paraoxonase

enzyme activity in general studying group, and controls.

Group

PON-1 192 Polymorphism

AA BB AB

mesenchymal confluence. We hypothesize that

exposure to oxidative stress promotes epithelial cell

apoptosis during palate formation. Oxidative stress

occurs when the production of reactive oxygen

species (ROS), including free radicals, exceeds the

handling capability of intracellular antioxidant

enzymes and extracellular antioxidant defenses.

Factors that may increase oxidative stress include

smoking, infections and inflammation, lower levels

of antioxidant production, and toxic exposures

(Blackburn, 2005; Agarwal et al., 2003). Defective

fusion in embryonic primary or secondary palate

has been reported in several mouse embryos and

explants exposed to xenobiotics, e.g. drugs and

various environmental pollutants such as dioxins or

nicotine derivatives (Saito et al., 2005). Excessive

oxidative stress leads to peroxidative damage to

cells, altered cellular function, and pathologic effects.

Paraoxonase (PON) is a serum enzyme that is

associated with antioxidative mechanism. The

paraoxonase gene maps to chromosome 7 (q21-23)

and has three separate genes, PON-1, PON-2 and

PON-3 (Primo-Parmo et al.,1996). Paraoxonase, a

45 kDa glycoprotein, that detoxify organophosphates

(Costa et al., 1999). It also serves HDL

associated protein, and with this function it protects

LDL against oxidation (Aviram et al., 1998). PON

1 has also been described to be related to the attributed

HDL anti-apoptotic function, since the ability

of HDL to protect against apoptosis is completely

lost when lipoprotein is oxidized (Matsunaga et al.,

2001). Moreover, it has also been shown thaat the

anti-apoptotic capacity is completely lost when

HDL is oxidized, and the lipoprotein becomes

proapoptotic to human aortic endothelial cell cultures

(Matsunaga et al., 2001). PON1 has two

common polymorphisms at codon 192 and 55. The

Total

Patient group 23 (29%) 14 (18%) 43 (54%) 80 (100%)

Control group 26 (49%) 6 (11%) 21 (40%) 53 (%100)

Total 49 (37%) 20 (15%) 64 (48%) 133 (%100)


70

A Gürsel Turgut et al.

192 glutamine (A)/arginine (B) polymorphism of

PON-1 gene is associated to enzyme activity and

also arginine 192 (B allele) isoform of enzyme

activity on reparing and detoxification processes

was more elevated in patients who have cardiologic

and diabetic problems (Ağaçhan et al.,

2005).

We analyzed PON-1 192 polymorphism in

cleft lip/palate patients and their family. The

purpose of this study was to assess the frequency

of polymorphisms of the PON1-192 genes in

nonsyndromic cleft lip and cleft palate patients

and matched control subjects.

Materials and methods

Data collection

All cases included in this study are from the medical

records of the Plastic, Reconstructive and

Esthetic Clinic of Şişli Etfal Research and Training

Hospital from August 2004 to January 2006.

50 nonsyndromic CL and CP cases and parents

were analyzed according to the following

variables: general information (gender, month

and year of birth), cleft type, maternal age, familial

history (hypertansion, malignancy and

having conjenital abnormality), associated malformations,

distribution of birth month. 45

healthy children and parents were also examined

as a control group.

Genotyping method of the paraoxonase 192

polymorphism

Blood specimens were collected in tubes containing

EDTA, and DNA was prepared from leukoycte

pellet by SDS lysis, ammonium acetate extraction

and ethanol precipitation. PON1 genotypes were

determined following PCR according to previously

published protocols (Miller et al., 1988).

For the 192 polymorphism, sense primer 5'

TAT TGT TGC TGT GGG ACC TGA G 3' and

antisense primer 5' CAC GCT AAA CCC AAA

TAC ATC TC 3' which encompass the polymorphic

region of the human PON1 gene were used.

The PCR reaction mixture contained 100 ng DNA

template, 0.5 M of each primer, 1.5 mM MgCl2,

200 M dNTPs and 1 U Taq DNA polymerase (MBI

Fermentas). After denaturing the DNA for 5 min at

94°C, the reaction mixture was subjected to 35

cycles of denaturing for 1 min at 95°C, 1 min annealing

at 60°C and 1 min extension at 72°C. The

99 bp PCR product was digested with 8 U BspI

restriction endonuclease (MBI Fermentas, Lithuania)

overnight at 55°C and the digested products

were separated by electrophoresis on 4% agarose

gel and visualised using ethidium bromide. The Bgenotype

(arginine) contains a unique BspI restriction

site which results in 66 and 33 bp products and

the A-genotype (glutamine) will not be cut allowing

the PON1 192 genotype to be determined (Adkins

et al., 1993).

Figure 1. The B-genotype (arginine) contains a unique BspI restriction site which results in 66 and 33 bp products

and the A-genotype (glutamine) will not cut allowing the PON1 192 genotype to be determined. AA: 99bp, BB: 66

and 33 bp, AB: 99, 66, 33bp.


Paraoxonase enzyme activity

Paraoxonase activities was measured according to

Furlong ( Furlong et al.,1989). The assay buffer

contains 0.132 M Tris HCl (pH 8.5), 1.32 mM

CaCl2 and 2.63 M NaCl. Addition of 200 µl of 6

mM freshly prepared paraoxon (o,o-diethyl-o-pnitrophenylphosphate;

Sigma, Poole, UK) and 40

Ìl of serum initiated the assay. The rate of generation

of p-nitrophenol was determined at 37°C,

with the use of a continuously recording spectrophotometer

at 405 nm. A molar extinction coefficient

of 18.05 x 10 3 was used for calculation

using paraoxon as a substrate. Pararaoxonase

activity is expressed as units/liter.

Statistical analysis

The statistical analysis was performed using the

commercially available software program (SPSS

12.0, SPSS Inc., Chicago, IL, USA). Association

between the disease and genotypes were tested

with Pearson Chi-Square test and Two-Sample

Kolmogorov-Smirnov Test. A probability of less

than 0,05 was required for statistical significance.

Results

We determined the frequencies for the 192A and

192B alleles; and the AA, BB, and AB genotypes

and paraoxonase enzyme activity in cleft lip/cleft

palate group, and controls (Table 1). AA genotype

was seen 33% in cleft lip/cleft palate group

and 32.5% in control group. AA genotype was

seen 48% in patients’s mothers and 24% in control

group’s mothers, and was seen 62.5% in

patients’s fathers and 28,8% in control group’s

fathers. BB genotype was seen 8.3% in cleft

lip/cleft palate group and 12.9% in control group,

and was seen 12% in patients’s mothers and 24%

in control group’s mothers. However it was seen

12.5% in patients’s fathers and 16.7% in control

group’s fathers. AB genotype was seen 58.3% in

cleft lip/cleft palate group and 54.8% in control

group and also was seen 40% in patients’s mothers

and 52% in control group’s mothers, however

was seen 25% in patients’s fathers and 52% in

control group’s fathers. There was no significant

differences in P192 genotype between mother,

father and children groups (Control group:

χ 2 =3.25, p=0.517; cleft lip/palate group: χ 2 =1.34,

p=0.855). There was no significant differences in

Paraoxonase-1 192 enzyme polymorphism 71

A

P192 genotype between case and control group

(χ 2 =5.70, p=0.058). When we assessed the P192

genotype randomly in mother, father and children

groups, there was no statistical difference (χ 2 =2.03,

p=0.730).

There was no statistical difference between in

cleft lip/cleft palate patient and control group

z=1.03, p=0.236). There was no statistically difference

between in cleft lip/cleft palate patient’s

mothers group and control group ( z=0.84, p=0.46).

There was no statistically difference between in

cleft lip/cleft palate patient’s fathers group and

control group (z=0.84, p=0.46).

There were any relationship between PON-1

192 polymorphism and cleft lip/ cleft palate patients

and their parents. Our study found no significance

in PON1-192 allele or genotype frequency

in cleft lip/cleft palate patients.

Paraoxonase enzyme activity

Paraoxonase enzyme activity has been evaluated

both in study group and control groups by using

paired samples test (t= paired sample test value).

Mean paraononase enzyme values were 145

units/liter in cleft lip/cleft patient, were 200

units/liter and were 190 units/liter in cleft lip/cleft

palate patient’s mothers, were in control group’s

mothers 216 units/liter (SD: 97) and were 156

units/liter in cleft lip/cleft palate patient’s fathers,

were in control group’s fathers 202 units/liter.

There was no statistical difference between cleft

lip/cleft palate patients and control group in paraoxonase

enzyme activity (t= 1.65, p= 0.107). The

same holds for the cleft lip/cleft palate patient’s

mothers group and control group (t= 0.75, p=

0.475). There was also no statistical difference

between cleft lip/cleft palate patient’s fathers group

and control group in paraoxonase enzyme activity

(t= 0.75, p= 0.475).

Arginine 192 (B allele) isoform of enzyme activity

on reparing and detoxification processes was

more elevated in patients who have cardiologic and

diabetic problems (Ağaçhan et al., 2005). However

AA genotype which is associated with low enzyme

activity in cardiologic and diabetic patients

(Ağaçhan et al., 2005) were not seen both cleft

lip/cleft palate children and their parents. Also we

did not assessed any significant difference in paraoxonase

enzyme activity between cleft lip/cleft

palate patient and control group. However it is

difficult to explain paraoxonase enzyme activity


72

A Gürsel Turgut et al.

cause of the enzyme activity is affected by enviromental

changes and personal psycological condition.

We could not find the adequate laboratory

assessment in the enzyme levels in the literature.

Discussion

The most important benefits of identifying the

genetic factors in disease susceptibility may not

be the potential for gene therapy, though it is an

exciting prospect. Rather, it should be the opportunity

for the treatment and prevention of clinical

disease by manuplating the enviroments of individuals

identified to be genetically at risk. The

low monozygotic concordance rate (25–50%) for

CL/P suggests that environmental factors are

involved. It is well recognized that alcohol (Murray,

2002) and smoking (Zeiger et al., 2005)

increase the risk for CL/P, and there is evidence

that folate supplementation decreases the risk

(Carmichael et al., 2003). Clearly it is likely that

the environment interacts with both the maternal

and fetal gene products, supporting the hypothesis

that genetic variation in involved pathways

modulates CL/P risk. Initial studies took a convenient

approach and looked for the interaction of

candidate genes and either smoking or alcohol.

Studies of gene-environment interaction in orofacial

clefting have evaluated candidate genes such

as TGFA, TGFB3, MSX1, BCL3, and RARA and

environmental behaviors including smoking,

alcohol use, and vitamin intake (Vieira et al.,

2005).

Myatt and Cui noted that pregnancy is a state

of oxidative stress arising from increased placental

mitochondrial (metabolic) activity and production

of ROS, mainly superoxide anion (Myatt and

Cui, 2004). Although maternal antioxidant capacity

increases during pregnancy, excessive oxidative

stress is seen in pregnancies complicated,

preterm labor, intrauterine growth restriction, and

miscarriage (Myatt and Cui, 2004). Excessive

oxidative stress leads to peroxidative damage to

cells, altered cellular function, and pathologic

effects. Paraoxonase is a serum enzyme that is

associated with antioxidative mechanism and is

well known for its ability to protect LDL against

oxidation. PON-1 has also been described to be

related to the attributed HDL antiapoptotic function,

since the ability of HDL to protect against

apoptosis is completely lost when lipoprotein is

oxidized. Moreover, it has also been shown thaat

the anti-apoptotic capacity is completely lost when

HDL is oxidized, and the lipoprotein becomes proapoptotic

to human aortic endothelial cell cultures

(Matsunaga et al., 2001). Taking these data together,

it may be hypothesized that PON-1 influences

the antiapoptotic ability of the HDL molecule. AA

genotype of PON-1 is associated with low enzyme

activity and in our study we have tried to explain

that there were any relationship between PON-1

192 polymorphism and cleft lip/ cleft palate patients

and their parents. Our study found no significance

in PON-1 192 allele or genotype frequency

in cleft lip/cleft palate patient. Also we did not

assessed any significant difference in paraoxonase

enzyme activity between cleft lip/cleft palate patient

and control groups. These results should be

interpreted with caution due to small numbers of

patients, but reinforces the need for very large scale

studies to provide a definitive answer.

References

Adkins S, Gan KN, Mody M and La Du BN.

Molecular basis for the polymorphic forms of

human serum paraoxonase/arylesterase:

glutamine or arginine at position 191, for the

respective A or B allozymes. Am J Hum Genet.

52: 598-608, 1993.

Agarwal A, Saleh RA, Bedaiwy MA. Role of reactive

oxygen species in the pathophysiology of

human reproduction. Fertil Steril. 79: 829–843,

2003.

Ağaçhan B.,Yılmaz H., Ergen A.,Karaali ZE, İsbir

T. Paraoxonase (PON1) 55 and 192 polymorphism

and its effects to oxidant-antioxidant system

in turkish patients with type 2 diabetes mellitus.

Physiol Res.54(3): 287-93, 2005.

Aviram M, Billecke S, sorenson R, Bisgaier C,

Newton R, Rosenblat m, Erogul j, Hsu C, Dunlop

C, La Du B: Paraoxonase Active Site required

for protection against LDL oxidation involves

its free sulfhydryl group and is different

from that required for its Arylesterase/Paraoxonase

activities: Selective Action Of

Human Paraoxonase Alloenzymes Q And R.

Arterio-Scler Thromb Vasc Biol. 18: 1617-

1624, 1998.

Blackburn S. Free radicals in perinatal and neonatal

care, part 1: the basics. J Perinat Neonatal

Nurs.19(4): 298-300, 2005.

Botto LD, Olney RS, Erickson JD: Vitamin supplements

and the risk for congenital anomalies


other than neural tube defects. Am J Med Genet.

125: 12-21, 2004.

Brunet, C.L., Sharpe, P.M., and Ferguson,

M.W.J. Inhibition of TGF-3 (but not TGF-_1

or TGF-_2) activity prevents normal mouse

embryonic palate fusion. Int. J. Dev. Biol. 39:

345, 1995

Carmichael SL, Shaw GM, Yang W, et al. Maternal

periconceptional alcohol consumption and

risk for conotruncal heart defects. Birth Defects

Res A Clin Mol Teratol. 67: 875-878,

2003.

Costa LG, Li WF, Richter RJ, Shih DM, Lusis A,

Furlong CE: The rol of paraoxonase (PON1)

in detoxification of orgonophosphates and its

human polymorphisms. Chem. Biol. Interact.119-120:

429-438, 1999.

Cuervo, R.,Valencia, C., Chandraratna, R.A.S.,

and Covarrubias, L. Programmed cell death is

required for palate shelf fusion and is regulated

by retinoic acid. Dev. Biol. 245: 145,

2002.

Das, S.K., Runnel, R.S., Smith, J. C., and Cohlx,

H. H. Epidemiology of cleft lip and cleft palate

in Mississippi.South. Med. J. 88: 437,

1995.

Ferguson, M.W., and Honig, L.S. Epithelialmesenchymal

interactions during vertebrate

palatogenesis. In E. F. Zimmerman (Ed.),

Current Topics in Developmental Biology,

Vol. 19. Palate Development: Normal and

Abnormal, Cellular and Molecular Aspects.

New York: Academic Pres. 137-164, 1984.

Finnell RH, Shaw GM, Lammer EJ, Brandl KL,

Carmichael SL, Rosenquist TH: Gene-nutrient

interactions: importance of folates and retinoids

during early embryogenesis. Toxicol

ApplPharmacol 198:75-85, 2004.

Forrester MB, Merz RD. Descriptive epidemiology

of oral clefts in a multiethnic population,

Hawaii, 1986-2000. Cleft Palate Craniofac J;

41:622-628, 2004.

Furlong CE, Richter RJ, Seidel SL, Costa LG,

Motulsky AG.Spectrophotometricassay for

the enzymatic hydrolysis of the active metabolites

of chlorpyrites and parathion by plasma

paraoxonase/arylesterase. Anal Biochemistry;

180: 242-7, 1989.

Gorlin RJ, Cohen MM, Hennekam RCM. Syndromes

of the head and neck. Oxford: Oxford

University Press; 2001.

Paraoxonase-1 192 enzyme polymorphism 73

A

Little J, Cardy A, Munger RG: Tobacco smoking

and oral clefts:a meta-analysis. Bull World

Health Organ. 82:213-218, 2004.

Martinez-Alvarez, C., Tudela, C., Perez-

Miguelsanz, J.,O’Kane, S., Puerta, J., and Ferguson,

M. W. J. Medial edge epithelial cell fate

during palatal fusion. Dev. Biol.220: 343, 2000

Matsunaga Y, Iguchi K, Nakajima Y, Koyama I,

Miyazaki T, Inoue I. Lycated high density induces

apoptosis of endothelial cells via a mithochondrial

dysfunction. Biochem Biophys Res

Commun; 287:714-720,2001.

Miller SA, Dykes DD, Polesky HS. Simples salting

out procedure extracting DNA from human

nucleated cells. Nucleic Acid Res. 16/3: 1215,

1988.

Munger RG, Sauberlich HE, Corcoran C, Nepomuceno

B,Daack-Hirsch S, Solon FS: Maternal vitamin

B-6 and folate status and risk of oral cleft

birth defects in the Philippines. Birth Defects

Res A Clin Mol Teratol. 70:464-471, 2004.

Munger RG: Maternal nutrition and oral clefts. In

Cleft Lip and Palate: from Origin to Treatment.

Edited by Wyszynski DFE. Oxford University

pres. 170-192, 2002.

Murray J. Gene/environment causes of cleft lip

and/or palate. Clin Genet . 61:248-256, 2004.

Myatt L, Cui X. Oxidative stress in the placenta.

Histochem Cell Biol.122:369–382, 2004.Cui X.

Oxidat

Primo-Parmo SL, Sorenson RC, Teiber J, Du BNL;

The Human Serum Paraoxonase/Aryesterase

Gene (PON1) Is One Member of a Multigene

Family. Genomics. 33:498-507, 1996.

Saito T, Cui XM, Yamamoto T, Shiomi N, Bringas

Jr P, Shuler CF. Effect of N- nitrosonornicotine

(NNN) on murine palatal fusion in vitro. Toxicology;

207:475-85, 2005.

Stanier P, Moore GE: Genetics of cleft lip and

palate: syndromic Hum Mol Genet, 13:73-81,

2004.

Vieira AR, Murray JC, Trembath D, et al. Studies

of reduced folate carrier 1 (RFC1) A80G and

5,10-methylenetetrahydrofolate reductase

(MTHFR) C677T polymorphisms with neural

tube and orofacial cleft defects. Am J Med Genet

A. 135:220-223, 2005.

Wyszynski DF. Cleft lip and palate: from origin to

treatment. Oxford: Oxford University Press;

2002.

Zeiger JS, Beaty TH, Liang KY. Oral clefts, maternal

smoking, and TGFA:a meta-analysis of


74

A Gürsel Turgut et al.

gene-environment interaction. Cleft Palate

Craniofac J. 42:58-63, 2005.

Zeiger JS, Beaty TH:Gene-environment interaction

and risk to oral clefts. In Cleft Lip and

Palate: from Origin to Treatment. Edited by

Wyszynski DFE. Oxford University pres.

283-289, 2004.

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