Genetic counseling in southern Iran: consanguinity and reason for referral

Experience in prenatal genetic testing and reproductive decision-making for monogenic disorders from a single tertiary care genetics clinic in a low-middle income country

OBJECTIVES

Explore health-care seeking behaviour among couples with pregnancies at-risk of monogenic disorders and compare time duration for obtaining Prenatal Genetic Test (PGT) results based on (i) amniocentesis and Chorionic Villus Sampling (CVS) (ii) in-house testing and out-sourced testing. Report the spectrum of monogenic disorders in our cohort.

METHODS

Medical records of women consulting prenatal genetic counselling clinic at Aga Khan University Hospital, Karachi from December-2015 to March-2021 with history of miscarriage or a monogenic disorder in previous children were reviewed.

RESULTS

Forty-three pregnancies in 40 couples were evaluated, 37(93%) were consanguineous. Twenty-five (63%) couples consulted before and 15(37%) after conception. Thirty-one (71%) pregnancies underwent CVS at the mean gestational age of 13-weeks and 6-days ± 1-week and 3-days and amniocentesis at 16-weeks and 2-days ± 1-week and 4-days. PGT for 30 (70%) pregnancies was outsourced. The mean number of days for in-house PGT was 16.92 ± 7.80 days whereas for outsourced was 25.45 ± 7.7 days. Mean duration from procedure to PGT result was 20.55 days after CVS compared to 28.75 days after amniocentesis. Eight (18%) fetuses were homozygous for disease-causing variant for whom couples opted for termination of pregnancy (TOP). Twenty-six monogenetic disorders were identified in 40 families.

CONCLUSION

Proactive health-care seeking behaviour and TOP acceptance is present amongst couples who have experienced a genetic disorder.

Interventions addressing genetic disease burdens within selected countries in the MENA region: a scoping review

BACKGROUND

The MENA region is disproportionately affected by genetic disease. The aim of this research is to scope the region for evidence of genetic services and public health interventions to identify geographic gaps, and to provide a descriptive overview of interventions to identify knowledge gaps.

METHODS

This study is conducted as a scoping review and follows the Arksey & O'Malley scoping review framework.

RESULTS

Seventy-six articles spanning 16 MENA nations met inclusion criteria. Studies included interventions in the form of genetic service provision (n=28), as well as comprehensive programs including pilot programs (n=7), community-based genetics programs (n=6) national-level prevention programs (n=18), and national-level mandatory programs (n=17).

CONCLUSIONS

There is an imbalanced response to genetic disease burdens across the MENA region. More research is warranted where interventions are scarce, particularly to inform development of pilot community-based programs. There is also a need for better monitoring and evaluation of existing nation-wide programs.

Social determinants of health and primary immunodeficiency

OBJECTIVE

Inborn errors of immunity (IEI) are rare genetic conditions affecting the immune system. The rate of IEI and their presentation, course, and treatment are all affected by a multitude of social determinants, eventually affecting prognosis. This review summarizes the current knowledge of the social determinants affecting infectious susceptibility, genetic predisposition, diagnosis, and treatment of IEI.

DATA SOURCES

PubMed.

STUDY SELECTIONS

Search terms included "consanguinity," "social determinants," and "founder effect." Further studies were selected based on relevant citations.

RESULTS

Changes in climate and human behavior have modulated the spread of disease vectors and infectious organisms. Consanguinity increases the rate of autosomal recessive conditions, changes the distribution, and affects the severity of IEI. Access to sophisticated genetic and immunologic diagnostic modalities affects genetic counseling and timely diagnosis. Effective genetic counseling should address to the patient's genetic background and ethical code. Access to appropriate and timely treatment of immunodeficiencies is scarce in some regions of the world.

CONCLUSION

High consanguinity rate and reduced access to prophylactic measures increase the burden of immunodeficiencies in many low- and medium-income countries. Furthermore, poor access to diagnostic and treatment modalities in these regions adversely affects patients' prognosis. Increased awareness among health care professionals and the public and increased collaboration with Western countries aid in diagnosis of these conditions. Further advancements require improved public funding to the prevention, diagnosis, and treatment of IEI.

Next-Generation Sequencing Identifies Pathogenic Variants in HGF, POU3F4, TECTA, and MYO7A in Consanguineous Pakistani Deaf Families

Background

Approximately 70% of congenital deafness is attributable to genetic causes. Incidence of congenital deafness is known to be higher in families with consanguineous marriage. In this study, we investigated the genetic causes in three consanguineous Pakistani families segregating with prelingual, severe-to-profound deafness.

Results

Through targeted next-generation sequencing of 414 genes known to be associated with deafness, homozygous variants c.536del (p. Leu180Serfs∗20) in TECTA, c.3719 G>A (p. Arg1240Gln) in MYO7A, and c.482+1986_1988del in HGF were identified as the pathogenic causes of enrolled families. Interestingly, in one large consanguineous family, an additional c.706G>A (p. Glu236Lys) variant in the X-linked POU3F4 gene was also identified in multiple affected family members causing deafness. Genotype-phenotype cosegregation was confirmed in all participating family members by Sanger sequencing.

Conclusions

Our results showed that the genetic causes of deafness are highly heterogeneous. Even within a single family, the affected members with apparently indistinguishable clinical phenotypes may have different pathogenic variants.

The status of PAH gene-VNTR alleles and mini-haplotypes associations with PAH gene mutations in Iranian Kurdish PKU patients

Background: The analysis of haplotypes/mini-haplotypes in the PAH gene has been used as an informative tool in several genetic anthropology studies. Considering the notion that Iranian population is one of the most heterogeneous i the world, this study was conducted to evaluate the association of VNTR-STR mini-haplotypes with the PAH gene mutations in PKU patients in Kermanshah province. Methods: A total of 24 unrelated Kurdish PKU patients with the known PAH gene causing mutations and 72 healthy controls were selected. The DNA fragments containing VNTR and STR systems were amplified by polymerase chain reaction (PCR). For VNTR system, PCR products were separated using electrophoresis on 2.5% agarose gel. For STR system, the samples were analyzed using DNA sequencing analysis version 5.2 software. Results: Overall, 5 PAH-VNTR-alleles, including VNTR3, 7, 8, 9, 12, and 3 PAH-STR-alleles, including STR238, 242, and 250, were detected in this study. VNTR3 and 8 alleles had the most frequency among healthy controls. Also, 6 different mini-haplotype alleles were found to be associated with PKU chromosomes. The 2 most prevalent mutations in Kermanshah province, IVS2+5G>C and IVS9+5G>A, were strongly linked to mini-haplotypes 9/242 and 8/238, respectively. Conclusion: The distributions and frequencies of VNTR alleles in Kurdish population have the most similarity to alleles previously described in European Caucasian families. Moreover, since the most common mutations in Kermanshah PKU chromosomes are rare and this was the first study on mini-haplotypes VNTR/STR among Iranian Kurdish PKU patients, given that this study was the first of its kind, it was not possible to compare its results with that of other studies on Iranian and non-Iranian populations.

Papillon-Lefèvre Syndrome: Diagnosis, Dental Management, and a Case Report

Aim

This paper revisits Papillon-Lefèvre syndrome (PLS), addresses its diagnostic update and dental management, and reports a case of a 5-year-old Lebanese patient with consanguineously married parents.

Background

PLS, also known as “keratoris palmoplantaris with periodontopathia” and “hyperkeratosis palmoplantaris with periodontosis,” is an extremely rare autosomal-recessive trait that combines a diffuse palmoplantar hyperkeratosis and a severe generalized, progressive prepubertal form of a precocious form of juvenile, aggressive periodontitis.

Case Description

We are reporting a 5-year-old boy that sustained a spontaneous loss of all his primary teeth. At consultation, he was under treatment for hyperkeratosis of his palms and soles. Detailed family history of the child revealed that the patient's parents, grandparents, and relatives were consanguineously married and two of his cousins displayed similar clinical signs (palmoplantar hyperkeratosis and premature loss of deciduous and most of the permanent teeth).

Conclusion

PLS is an extremely rare disorder that usually becomes apparent from approximately 1-5 years of age. Genetic counseling should always be suggested to parents of affected children, informing them of chances of their offspring having the inherited disease.

A review of the reproductive consequences of consanguinity

BACKGROUND

Consanguinity is the close union, sexual relationship or marriage between persons who have common biological ancestors usually up to about 2nd cousins. Contrary to general opinion consanguinity is quite common and is practiced worldwide. It is an important topic as while rates of consanguineous unions in certain society have decreased over time, rates have remained stable or increased in other societies with rates as high as 80.6% in some communities. Our aim was to conduct a review looking at general aspects of consanguinity and any published reproductive outcomes in literature. We also looked at possible future directions that could be relevant in the management of the consanguineous couple to help improve reproductive outcomes.

METHOD

We conducted a PUBMED, CINAHL, Web of Knowledge and Google Scholar search looking at articles on consanguinity. Consanguinity articles related to pregnancy and reproduction were searched using additional filters looking at our specific areas of interest. All relevant publications up to March 2015 were reviewed. Additional search for relevant articles pertaining to pre implantation genetic diagnosis for future directions in the management of the consanguineous couple was done. Most publications were found in books, on line articles and journals. Most were retrospective, population or cohort studies.

RESULT

Consanguinity is practiced by up to 10% of the world's population with rates ranging from 80.6% in certain provinces in the Middle East to less than 1% in western societies. It predates Islam and has been practiced since Old Testament times. The most commonly cited reason for consanguinity is sociocultural and socioeconomic although it is also more common in certain religions. In areas where rates of Consanguinity are reducing urban migration and increasing education rates are thought to be contributory. Congenital malformations have long been established to be higher in consanguineous couples above the background rate (4.5% Vs 1%).Due to "Founder effect" or a common ancestor, Consanguinity is most commonly associated with Inborn errors of metabolism most of which are autosomal recessive. Consanguinity increases the incidence of multifactorial disorders such as diabetes, cardiovascular disorders, obesity and certain types of cancers. These may in turn affect reproductive outcomes. It may also affect fertility rates. Pregnancy outcomes like increased pregnancy wastages and preterm labor have been reported with consanguinity. Other studies produced conflicting evidence on its effect regarding outcomes like hypertensive disorders of pregnancy and Intrauterine growth restriction.

CONCLUSION

Consanguinity continues to be practiced worldwide and in some countries rates are increasing. The main reason for the practice appears to be sociocultural and socioeconomic although religious beliefs is a contributory factor. The most significant effects on reproductive outcomes are mostly due to autosomal recessive inherited conditions and inborn errors of metabolism. It also significantly increases the inheritance of certain multifactorial disorders like diabetes which may indirectly affect reproductive outcomes. In the future with the completion of the study of the whole human Genome and current advances in Pre implantation Genetic diagnosis and screening it may be possible to mitigate some of the adverse reproductive outcomes associated with consanguinity.

The genetic background of Southern Iranian couples before marriage

Genetic service for couples plays an increasingly important role in diagnosis and risk management. This study investigated the status of consanguinity and the medical genetic history (effectiveness and coverage of medical genetic services) in couples residing in a city in southern Iran. We questioned couples who were referred to Behbahan Marital Counseling Center, Behbahan, Iran, during the period from January to November 2014, to obtain information on consanguinity, disease history, and previous referral to a medical genetics center. For the collected data was obtained descriptive statistics with STATA 11.0 software. A total of 500 couples were questioned. Mean age was 24.8 ± 5.2 years. Almost one quarter (23.4%) of the couples were consanguineous. Consanguinity was almost twice as common in rural areas as in urban areas (33.9 vs. 19.2%, p = 0.001). Only a few couples (~3.0%) had ever been referred for genetic counseling. The main reason for previous genetic counseling was consanguinity (85.7%). The majority of the participants (96.3%) had never been tested for any genetic conditions. Our findings suggest that only a small proportion of couples in Khuzestan Province, Iran (Behbahan City) were receiving adequate genetics care. This may reflect the limited accessibility of such services, and inadequate awareness and education among the care providers.

Prevalence of Keratoconus among Young Arab students in Israel

Purpose

To determine the prevalence of keratoconus (KC) in an Arab population in Israel.

Materials and methods

Videokeratography was performed on volunteer students from the Academic Arab College of Education, in Haifa, Israel. All participants filled out a self-administered questionnaire to evaluate possible risk factors for KC. Univariate and multivariate analysis were performed.

Results

Data of 314 participants were analyzed and a prevalence of (N = 10), 3.18% (95% CI, 1.2 to 5.1%) was found. The only significant factor (both in univariate and multivariate analysis) that was associated with KC was parental consanguinity (OR 5.10, p = 0.02). Druzes and Bedouins had a higher prevalence than Muslims and Christians. However, the differences were not significant possibly due to the small size of the sample.

Conclusion

The result of this study was similar to other studies conducted in the Middle East, which indicate a higher prevalence of KC than in western countries. It is also recommended that people who have consanguinity in their family should be topographically tested to detect the early stages of KC.

How to cite this article

Shneor E, Millodot M, Gordon-Shaag A, Essa M, Anton M, Barbara R, Barbara A. Prevalence of Keratoconus among Young Arab Students in Israel. Int J Kerat Ect Cor Dis 2014;3(1):9-14.

Prenatal genetic counseling and consanguinity

OBJECTIVES

To evaluate the prevalence of consanguineous patients at a Western European prenatal genetic counseling clinic and to describe demographic as well as health-related characteristics of this patient group.

METHOD

Retrospective analysis of 1964 primary consultations at the Prenatal Genetic Counseling Outpatient Clinic at the Medical University of Vienna General Hospital in Austria. Characteristics of consanguineous patients were compared with those of a control group of not-related unions.

RESULTS

A total of 8.9% (174/1964) of all patients lived in a consanguineous union, meaning they were related as second cousin or closer [78.7% (137/174) first cousin, 14.4% (25/174) second cousin, 6.3% (11/174) first cousin once removed or 0.6% (1/174) uncle/niece]. Consanguineous patients were significantly younger (26.6 ± 5.4 vs 30.4 ± 6.5, p < 0.01) and of non-Austrian background [92.5% (161/174) vs 32.8% (57/174), p < 0.01] than not-related controls. Forty-six per cent (80/174) were referred during an ongoing pregnancy. The main counseling issue was family history of consanguinity (ICD Z84.3) in 31.6% (55/174) of cases.

CONCLUSIONS

Estimations of the prevalence of consanguinity among the general population in Western Europe likely highly underestimate the evaluated prevalence among patients referred for prenatal genetic counseling. Counseling strategies need to take into consideration that consanguineous patients are more likely to be young and have an immigrant background.

Health beliefs and practices of Qatari women: A qualitative study

The purpose of this study was to understand health beliefs and practices of Qatari women by exploring puberty and sexual relations. A qualitative descriptive research design, using focus groups, was used in this study. Purposive sampling was used to recruit college-age Qatari women from six universities in Qatar. A total of 43 Qatari women participated in this study. NVivo 8 qualitative analysis software was used to analyze collected data. Participants reported that Qatari women lacked information about puberty and did not feel prepared for their first menstrual period (menarche). Participants also reported a lack of information about sexual relations due to their mothers’ and schools’ discomfort with the topic. Recommendations related to the investigated areas were elicited from the participants. There is a urgent need to conduct educational programs in Qatar.

Consanguineous marriages : Preconception consultation in primary health care settings

Consanguinity is a deeply rooted social trend among one-fifth of the world population mostly residing in the Middle East, West Asia and North Africa, as well as among emigrants from these communities now residing in North America, Europe and Australia. The mounting public awareness on prevention of congenital and genetic disorders in offspring is driving an increasing number of couples contemplating marriage and reproduction in highly consanguineous communities to seek counseling on consanguinity. Primary health care providers are faced with consanguineous couples demanding answers to their questions on the anticipated health risks to their offspring. Preconception and premarital counseling on consanguinity should be part of the training of health care providers particularly in highly consanguineous populations.

Mutation analysis of the CYP21A2 gene in the Iranian population

BACKGROUND

Defects in the CYP21A2 gene cause steroid 21-hydroxylase deficiency, which is the most frequent cause of congenital adrenal hyperplasia. Forty four affected families were investigated to identify the mutation spectrum of the CYP21A2 gene.

METHODS

Families were subjected to clinical, biochemical, and molecular analyses. Allele-specific polymerase chain reaction amplification was used for eight common mutations followed by dosage analysis to exclude CYP21A2 deletions.

RESULTS

The most frequent mutations detected were gene deletions and chimera (31.8%). Other mutation frequencies were as follows: Q318X, 15.9%; I2G, 14.8%; I172N, 5.8%; gene duplication, 5.7%; R356W, 8%; and E6 cluster mutations, 2.3%. Direct sequencing of the CYP21A2 gene revealed R316X, P453S, c.484insT, and a change at the start codon. Different modules carried by patients were classified into five different haplotypes. The genotype phenotype correlation (positive predictive value) for group null, A, B, and C were 92.3%, 85.7%, 100%, and 0, respectively.

CONCLUSIONS

Methods used will be helpful for carrier detection and antenatal diagnosis, especially with inclusion of the multiplex ligation probe dependent amplification technique, which is easier for routine tests in comparison with other methods. Mutation frequencies indicate that Iranians are possible descendants of Asians and Europeans.

Is there a significant trend in prevalence of consanguineous marriage in Tehran? A review of three generations

Consanguineous marriage is a common practice in Iran. The present study surveyed the trend in consanguineous marriage across three generations of Iranians. Index cases, consisting of 400 individuals attending the diabetes and osteoporosis clinic in Shariati Hospital, were interviewed. Data on consanguinity status for 1789 marriages within the index cases' families were obtained. Generation 1 consisted of marriages contracted before 1948, Generation 2 consisted of marriages contracted between 1949 and 1978, and Generation 3 consisted of marriages contracted after 1979. Prevalence of consanguineous marriage within these three generations was 8.8%, 16.6% and 19%, respectively, and represented a significant trend (p < 0.001). First cousin marriage was the most common type of consanguinity (69%). Socioeconomic level of families was not significantly related to having a consanguineous marriage. These data suggest that premarital genetic counseling and mass media efforts are needed to increase public awareness about genetic risks associated with consanguineous marriage.