Cytogenetic Evaluation of Cleft Lip and/or Palate

Case Series

Austin J Genet Genomic Res. 2024; 5(1): 1024.

Cytogenetic Evaluation of Cleft Lip and/or Palate

Osman Demirhan*

Department of Medical Biology and Genetics, Faculty of Medicine, Çukurova University, Balcali- Adana/Turkey

*Corresponding author: Osman Demirhan, Prof. PhD Çukurova University, Faculty of Medicine, Department of Medical Biology and Genetics, Adana-Turkey. Email: odemirhan42@gmail.com; osdemir@cu.edu.tr

Received: December 19, 2023 Accepted: January 17, 2024 Published: January 23, 2024

Abstract

Purpose: It is known that the possible causes of congenital defects such as common cleft palate and/or libidinal (CLP) are multifactorial and occur as a result of genetic and environmental risk factors. Although these defects appear to have a genetic cause, the cause of most cases is still unknown. In this study, the relationship of CLP to possible cytogenetic causes was evaluated. In this study, the relationship of CLP with possible cytogenetic causes was evaluated.

Material and Methods: In this study, conventional karyotyping was performed on 10 patients who were referred to our genetics laboratory with complaints of cleft lip and/or palate.

Results: Structural and numerical CAs were found in four of the 10 patients with CLP, and a normal karyotype was found in 6 of them. Two male patients had XXY karyotype, one had 22q12 trisomy and one had pericentric inversion on chromosome 9.

Conclusion: Our findings support that X chromosome abundance and dosage of some genes in the 22q12 region may affect the development of cleft palate and lip and contribute to CLP. However, it has provided new opportunities for the understanding of orofacial cleft (OFC) biology and clinical research and has demonstrated the need to provide medical-genetic counseling to parents of children with gene and chromosomal disorders.

Keywords: Cleft lip and palate; Etiology; Sitogenetics; XXY karyotype; 22q12 trisomy

Introduction

CLP is the most common and best-known congenital orofacial birth defect in humans. There has recently been evidence to support a multifactorial inheritance pattern. In a large series of patients, some appear to result from single mutant genes, some from chromosomal abnormalities, some from specific environmental agents, and some from the interaction of many genetic and environmental differences, each with a relatively minor effect [1]. The average incidence for CL/P is reported to be around 1 in 700 newborns [2,3]. A cleft palate is seen in 1 in 1500 newborn babies. The incidence of cleft lip and palate in Turkey has been reported as 1.1 per thousand, and the incidence of isolated cleft palate as 0.77 per thousand [4]. Although these defects seem more likely due to a genetic cause, the cause of most cases is still unknown. These defects may occur alone or as part of a wide variety of chromosomal, gene, or teratogenic syndromes. Although significant progress has been made in identifying genetic and environmental triggers for syndromic ones, the etiology of non-syndromic forms has not yet been fully defined. Because of the heterogeneous etiology of CLP, it is necessary to know the biology of facial development and how environmental risks interact with genetic factors. Genome-wide linkage and association studies have identified new loci with significant relevance. There are significant phenotypic differences in individuals and family members with orofacial cleft birth defects, and the incidence of structural and numerical chromosomal changes in patients has been reported as 3.6% [5]. This study may provide information to better interrogate cytogenetic analysis for loci other than CLP-related coding regions. Our knowledge on this topic is largely biased, so more extensive research is needed to understand the mechanisms underlying these defects.

Methodology

Methods

Ten children from the pediatric clinic with complaints of cleft palate and lip were sent to our laboratory for genetic analysis. The male/female ratio of the cases was 4/6 (0.7), the mean gestational week was 37.7, and the mean maternal age was 26.0. These children ranged from 17 days to 3 years (mean 1.2 years). There was only cleft palate in one of the cases, and both cleft palate and lip in the others. A seventeen-day-old boy with cleft lip and cleft palate was admitted to the neonatal service because he could not be fed. The patient's parents were the first children of a 25-year-old mother and a 27-year-old father, who were second-degree relatives. There was no similar disease in her family history, and her physical examination revealed a low ear, hypertelorism, bilateral cleft lip, and complete cleft palate deforming the nasal root, low hairline, and pes equinovarus (Figure 1,2). A three-year-old boy was sent for genetic analysis for unilateral cryptoorchidism. The patient had previously been operated for cleft palate and lip, and there were surgical scars on the upper lip and philtrum (Figure 3,4). The patient's parents were related, he was the first child of a 23-year-old healthy mother and 29-year-old healthy father, and there was a diagnosis of CLP in his family history. Other children were those with only cleft palate or cleft lip and palate defect without any other congenital defect. There was consanguineous marriage between the parents of four cases. Conventional karyotyping was performed using 4 ml of peripheral blood for sowing, harvesting, banding, and analysis. All procedures performed in studies were in accordance with the ethical standards of the institutional and/or national research committee (Scientific Research Ethics Committee Directive) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Citation: Demirhan O. Cytogenetic Evaluation of Cleft Lip and/or Palate. Austin J Genet Genomic Res. 2024; 5(1): 1024.