The Effect of Consanguineous Marriages in Solving DNA Cases

2021 ◽  
pp. 1-13
Author(s):  
Noora R. Al-Snan ◽  
Fatima J. AlBuarki ◽  
Samreen S. Sayed
1956 ◽  
Vol 6 (1) ◽  
pp. 41-49 ◽  
Author(s):  
L.D. Sanghvi ◽  
D.S. Varde ◽  
H.R. Master

2021 ◽  
pp. 1-11
Author(s):  
Seda Susgun ◽  
Koray Kasan ◽  
Emrah Yucesan

<b><i>Background:</i></b> In the context of medical genetics, gene hunting is the process of identifying and functionally characterizing genes or genetic variations that contribute to disease phenotypes. In this review, we would like to summarize gene hunting process in terms of historical aspects from Darwin to now. For this purpose, different approaches and recent developments will be detailed. <b><i>Summary:</i></b> Linkage analysis and association studies are the most common methods in use for explaining the genetic background of hereditary diseases and disorders. Although linkage analysis is a relatively old approach, it is still a powerful method to detect disease-causing rare variants using family-based data, particularly for consanguineous marriages. As is known that, consanguineous marriages or endogamy poses a social problem in developing countries, however, this same condition also provides a unique opportunity for scientists to identify and characterize pathogenic variants. The rapid advancements in sequencing technologies and their parallel implementation together with linkage analyses now allow us to identify the candidate variants related to diseases in a relatively short time. Furthermore, we can now go one step further and functionally characterize the causative variant through in vitro and in vivo studies and unveil the variant-phenotype relationships on a molecular level more robustly. <b><i>Key Messages:</i></b> Herein, we suggest that the combined analysis of linkage and exome analysis is a powerful and precise tool to diagnose clinically rare and recessively inherited conditions.


2011 ◽  
Vol 18 (04) ◽  
pp. 638-643
Author(s):  
AMMAR ANWER ◽  
ALI SHAKEEL ◽  
M. HAMAYUN IKRAM ◽  
Shahroona Masud Zaman

Objective: This study was carried out to find out the prevalence of Jervell and Lange Nielsen Syndrome (JLNS) in deaf school children for impaired hearing and to correlate this with consanguineous marriages. Setup: Schools for deaf and dumb children and Sheikh Zayed Medical College, Rahim Yar Khan. Design: Cross sectional, case control study. Period: 2006 - 2007. Methods: Electrocardiographs (ECG’s) of 114 congenitally deaf school children (ages 4-20 years) and also of 23 healthy children with normal hearing function of same age group were recorded. The corrected QT (QTc) interval of all 137 ECGs was evaluated by Bazett’s formula. Mean QTc of healthy children was taken as reference of normal QTc interval. The deaf children with normal QTc were labeled as control group. Patients with long QTc were further evaluated for JLNS by applying Schwartz’s criteria. We also calculated the relationship of the positive cases to consanguineous marriages. Results: We found that 28 deaf children out of 114 cases had QTc intervals longer than 0.44 seconds. This interval was significantly longer [P=0.008] than the QT interval in control group. As per Schwartz’s criteria, 15 out of 28 LQTs cases scored high points (3.5 to 5.5). The presence of consanguineous marriage was 100% in first pedigree of these 28 children. Conclusions: JLNS (an alarming arrhythmic disease associated with congenital deafness) is significantly present (24.6%) in Rahim Yar Khan’s deaf school children. The presence of cousin marriage was 100% in first pedigree of these children.


1995 ◽  
pp. 45-53
Author(s):  
Jaakko Ignatius

The frequency of marriages contracted between individuals with close consanguinity has traditionally been low in Finland. In the 19th and early 20th centuries only 0.1-0.3% of all marriages were contracted between first-cousins (average kinship coefficient 0.0001-0.0002). In genealogical search, however, a remote consanguinity (often beyond 3rd cousins) is frequently found especially in the rural areas and the true level of inbreeding is higher. In Finland, several autosomal recessive diseases are known to be enriched in the population. This unique spectrum of genetic diseases is sometimes called »the Finnish Disease Heritage». To study the implication of close consanguinity for these disorders, information on consanguineous marriages closer than second-cousins was collected from 808 families representing 24 different »Finnish» autosomal recessive disorders. The mean rate of first-cousin marriages was 1.6% (0-20%). Consanguinity (parents second-cousins or closer) was found in 4.2% of the families. For comparison, in 160 families representing three »non-Finnish» autosomal disorders the corresponding figures were 1.9% and 2.5%, respectively. Although these figures are high when compared to the general Finnish population, it can be concluded that close consanguinity is not a significant factor of Finnish genetic diseases.


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