Association of the P561T and C422F polymorphisms of the growth hormone receptor gene with facial dimensions.

Abstract

Background: Growth hormone plays a significant role in determining craniofacial morphology. Mutations of its receptor gene might be associated with mandibular prognathism (MP). Purpose: The aim of the current study was to evaluate growth hormone receptor (GHR) gene polymorphisms in relation to facial dimensions. Material and Method: The study enrolled 65 participants with class III profile in MP group and 60 orthognathic control participants. Genomic DNA was extracted from a blood sample from the patients and the P561T and C422F polymorphisms of GHR gene were screened by PCR-RFLP method followed by Sanger sequencing of randomly selected samples to validate the genotyping results. Chi square was used to compare distribution of polymorphism in MP and control groups (p<0.05). Results: Heterozygous P561T mutation was found in 10.77% and 8.33% of MP and control groups, respectively (p=0.644) while none of the subjects had the C422F mutation. Sanger sequencing confirmed the genotyping results from the PCR-RFLP method. P561T polymorphism was significantly associated with ramus and lower facial height in MP patients and with ramus height in orthognathic patients (p<0.05). Conclusion: The results indicate that the P561T polymorphism of the GHR gene is associated with the vertical dimension of the mandible in an Iranian population.

Genetic effect of single nucleotide polymorphisms in growth hormone receptor gene on the risk of non‐syndromic mandibular prognathism in the Korean population

“…However, no significant association did not find in males and females (Table 2). These results were consistent to previous studies of Korean, Japanese, Iran, Colombian, and Turkish population 19,29‐32 …”

“…However, other studies 19,32 reported that subjects with major allele homozygote of rs6182 and rs6184 showed the greater mandibular RH than subject with heterozygotes. These inconsistencies may be due to different genotype and allele frequencies in population and sample size.…”

“…In comparison between heterozygote and major allele homozygote of rs6182 and rs6184, studies 30‐32 reported that subjects with heterozygotes of rs6182 and rs6184 had a greater mandibular RH than subjects with major allele homozygotes. However, other studies 19,32 reported that subjects with major allele homozygote of rs6182 and rs6184 showed the greater mandibular RH than subject with heterozygotes. These inconsistencies may be due to different genotype and allele frequencies in population and sample size.…”

“…These results were consistent to previous studies of Korean, Japanese, Iran, Colombian, and Turkish population. 19,[29][30][31][32] Craniofacial phenotype clearly differs between males and females especially in mandible, and these differences are driven by growth timing of mandible and by the influence of sex hormones during growth and development, which in turn, may affect mandibular morphology and size. 33 Especially, adult MP has been associated with sexual dimorphism.…”

“…These findings were consistent with previous studies. [30][31][32] In comparison between heterozygote and major allele homozygote of rs6182 and rs6184, studies [30][31][32] reported that subjects with heterozygotes of rs6182 and rs6184 had a greater mandibular RH than subjects with major allele homozygotes.…”