Mendelian and Rare Diseases

POLYMORPHISM  IN EXON 7 OF ENDOTHELIAL NITRIC OXIDE SYNTHASE

ASSOCIATION OF G894T POLYMORPHISM  IN EXON 7 OF ENDOTHELIAL NITRIC OXIDE SYNTHAESE  ( eNOS GENE ) WITH DIABETIC SEPTIC FOOT PREDISPOSITION IN SUDANESE

    Authors:

Shaza Esmat Omer Mohamed Ali ¹ , Mohamed Mahmoud Mohammed Ahmed ²,  and Manal Ahmed  M. A . Fadl³ .

¹ Department of Biotechnology ,Juba university .

 ² Fellowship  of Sudan Medical Specialization board

³Assistant professor of Molecular Biology –Alneelain  University

Diabetic septic foot is complication of diabetes and leads to amputation of extremities with high morbidity rate. In Sudan the prevalence of DSF is increasing and genetic role was evidenced .

The endothelial nitric oxide synthase (eNOS) encoded by the NOS3 gene is responsible for the synthesis of endothelium-derived nitric oxide (NO) with function include vasodilation  ,neurotransmitter, neuroprotective ,pain perception , and vasoprotective .The    polymorphism of G to T at nucleotide 894 in exon 7 of eNOS  gene  change    eNOS structural   and activity leading to   endothelial dysfunction and  then  impaired wound healing .

This  cross sectional study was carried out to examine the association of SNP (G894T) of  eNOS gene with Sudanese  DSF patients using blood sample from 53  diabetic patients as control and 62  DSF patients as cases  with clinical and demographic data   questionnaire without  restriction to age, gender, race or disease.

DNA from blood sample was extracted using guanidine chloride method and its   quality and quantity was  measured  using electrophoresis and nanaophoto-meter  respectively  and  then DNA was  amplified in PCR thermo cycler whereas genotyping and alleles percentages was detected using restriction fragment length polymorphism (RFLP) technique .

 Results showed no  association of G894T polymorphism of the (eNOS) gene with DSF  (P= 0.105)which may be explained by gene pools ,environmental factors and neuropathy  which detected in 68.8%of DSF increasing  the risk of DSF predisposition 3.7 folds   Moreover, the T mutant allele was frequent among both DSF(91.1%) and DM(81.1%)  patients .

Also high frequency of males among DSF(83.8%) with a significant gender difference between DSF and DM patients (P= 0.00)  may be attributed to smoking, sensitivity to insulin and negative  effect of androgens hormone on wound healing.

The low socioeconomic status among DSF (95.7%) was  significantly  difference   (P=0.00) which  may be regarding  to  lack of foot care and treatment  .

 

 

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Genetic epidemiology of rare autosomal recessive disorders and genome research 

Genetic epidemiology of rare autosomal recessive disorders and genome research 

 

Giovanni Romeo M.D.

European School of Genetic Medicine (www.eurogene.org)

 

Understanding the medical genetics needs of any inbred community requires the knowledge of a few basic concepts of genetic epidemiology. I will start from the theoretical foundations which predict the frequency of alleles associated with rare autosomal recessive (RAR) disorders and are based on the study of children of consanguineous marriages, as established in the pre-molecular era by the Swedish geneticst Dahlberg. He first noticed in 1943 that the proportion of consanguineous parents of children affected with any RAR disorder is inversely proportional to the frequency of the mutated gene in the general population (q). In Italy it was possible to calculate q for PKU, Friedreich ataxia and CF even before the cloning of the respective genes using the “Vatican Archive” of consanguineous marriages, created 50 years ago by Cavalli-Sforza and coworkers, which documents the variations in time and space of consanguineous marriages in the general population broken down for the different Italian regions and provinces for five years periods during almost 400 years (1600–1964).

The probability that a child of consanguineous parents carries two copies of the same allele identical by descent (IBD) is called autozygosity (=homozygosity by IBD). Then if one knows precisely the frequency of consanguineous marriages in the general population (C) for any given time period and population subgroup (e.g. from the Vatican Archive) and the proportion of consanguineous parents of children affected with a given RAR disorder (C’) in the same population, q can be accurately calculated following Dahlberg’s approach.

Today a more efficient epidemiological approach based no longer on demographic data but on molecular data (defined Homozygosity Index: HI) makes it possible to estimate q for a RAR disorder if one knows the mutational spectrum, the proportion of truly homozygous patients determined by mutation analysis and the inbreeding coefficient estimate (F) in a small sample of affected individuals. This result was achieved for PKU and Mediterranean Fever in Lebanon and Turkey, for  Wilson disease in Sardinia and more recently for Congenital Adrenal Hyperplasia ( CAH) in mainland Italy and Sardinia (Gialluisi et al. Clin. Genetics, 93, 223-227, 2018).

In conclusion these epidemiological studies based on consanguinity have originated an interesting strategy useful for planning public health policies regarding the prevention of RAR disorders in the genomic era. First of all, the inbreeding coefficient (F) can be calculated using genomic data (like SNP data) which make the HI approach easier and more precise. Moreover causative mutations associated with RAR disorders lie in Regions of Homozygosity (ROH) and can be identified more easily in consanguineous families, as done for example by Whole Exome Analysis in the case of the MYO15A frameshift duplication which represents the  major cause of Genetic Hearing Loss (GHL) in Oman (Pippucci et al. J. Human Genetics, 62: 259–264 (2017) doi:10.1038/jhg.2016.120).

 

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Profound biotinidase deficiency

Profound biotinidase deficiency caused by (D444H) resulting in recurrent early childhood death in a Sudanese Family

Authors and Affiliations

Reem Salaheldin, Rayan Ali, Muntaser E Ibrahim, Imad Fadel-Elmula.

 

Introduction

Biotinidase deficiency (BTD) is an autosomal recessive disease in which biotin recycling from biocytin or biotinylated peptides is impaired. The disorder is caused by absent or markedly deficient activity of biotinidase.

Material and methods

Two healthy parents presented with history of two daughters who had neurological cutaneous and respiratory manifestations who died at early childhood. They also had two healthy living daughters (8;4 year-old). Whole exom sequencing was done for the mother and then specific BTD gene sequencing was done for the father which were analyzed through bioinformatic tools.

Results: whole exom sequencing analysis of the mother genomic DNA showed heterozygous missense mutation in BTD gene with rs 13078881 was found. Identical mutation was latter identified also in the father DNA.

Discussion: This present mutation behaved in unusual way since it caused profound biotinidase deficency in homozygous state. According to our knowledge this the first ever case with profound biotinidase deficency in homozygous state to be reported.

Conclusion: In the absence of neonatal screening programmes whole genome sequencing remain the only effective way of diagnosis metabolic Mendelian disorders in underdeveloped countries.

 

 

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MUTATIONS IN SUDANESE PATIENTS SUSPECTED TO HAVE ALPHA THALASSAEMIA

SCREENING FOR 3.7 AND 4.2 DELETION MUTATIONS IN SUDANESE PATIENTS SUSPECTED TO HAVE ALPHA THALASSAEMIA

Hussam Ali Osman1*, Sana Altahir Abdallah2
1* Biotechnology Research Laboratory, School of Pharmacy, Ahafad University for Women, Omdurman, Sudan.
2 Department of Pathology, Faculty of Medicine, Alneelain University, Khartoum, Sudan.
Keywords: Alpha Thalassaemia, Homozygous, Heterozygous, Deletion mutations, GAP-PCR
Corresponding author: Hussam Ali Osman1*
Tel: +249-911000732 Fax: +249-187579111 Email: hussomco@gmail.com

Abstract:
Background: Alpha-thalassaemia is the genetic disorders, characterised by microcytic and hypochromic anaemia. Aim: The study aimed to screen the participant blood samples for the most common types of the alpha thalassemia mutations in Africans (3.7 and 4.2 deletion mutations) and to correlate the findings with the CBC parameters. Methods: A cross-sectional study targeted 98 patients of highly suspected to have alpha thalassemia. Results: Revealed of these 98 patients, 7 were carriers for the 3.7 deletion mutation and only one patient was 3.7 homozygous deletion mutation, while all samples were negative for the 4.2 deletion mutation. The 3.7 deletion mutation was found in a Sudanese tribe of Four, Hawsa, and Rezagat, which originated from the West Africa. In the carriers of the 3.7 deletion mutation, the RBCs and HCT were significantly increased “P-value <0.05”. The RBCs were 7.230.78×1012/L in adult males and 7.210.67×1012/L in adult females while in children were 5.070.87×1012/L. The MCV and MCH were clearly decreased, but the MCHC slightly decreased. The Hb levels revealed mild decrease without statistical significance “P-value ˃0.05” in adult males were 11.70.57 g/dl and 11.250.64 g/dl in adult females while in children were 11.62.95 g/dl. The Ferritin levels were normal and the RDW_CV% means were clearly increased. The quantitative Hb electrophoresis was normal in addition to the presence of many target cells in peripheral blood picture and no one of these carriers presence with clinical manifestations indicating for anemia, but the homozygous 3.7 deletion mutation patient was anemic and his basic hematological parameters were as follows RBCs 1.38×1012/L, Hb 4.99 g/dl, HCT 11%, MCV 79.7 fl, MCH 35.5 pg, MCHC 44.5 g/dl, RDW_CV 17.7% and his Ferritin level was1807 mg/dl and this elevation due to blood transfusion. Conclusion: Confirmed the presence of the alpha thalassemia in Sudanese population for the 3.7 deletion mutation.

Name, title and affiliations of presenter:

Dr. Hussam Ali Osman (PhD)
Assistant Professor of Haematology
Ahfad University for Women
School of Pharmacy
Biotechnology Research Laboratory

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Safaa Momoun

Genetics of susceptibility to fibromyalgia among Sudanese population

Safaa Ali Taha, Hassan Yousif, Mathaba Madani and Hind Abushama, University of Khartoum Faculty of Science department of Zoology

Aim

The aim of this study is to investigate the association between single nucleotide polymorphism COMT rs4680 (Val158Met) that has three polymorphisms: Val\Val, Val\Met, Met\Met with risk of developing fibromyalgia.

Background

Fibromyalgia syndrome is an idiopathic medical condition characterized by lower pain threshold and chronic disabling pain. Fatigue and tenderness of muscles that persist for more than three months. The raising number of cases in Sudan with lack of proper diagnosis to the cases is the main factor for suggesting this research problem. Recent studies showed that fibromyalgia onset begins after psychological or physical trauma, like physical pain caused by autoimmune diseases or cancer. Studies also revealed that fibromyalgia syndrome showed familial aggregation, which indicate the genetics factor of fibromyalgia.

Methods

Samples have been collected from primary and secondary fibromyalgia patients. Rheumatoid arthritis patients and healthy control have been considered in this study. Sixty volunteers participated in this study. Samples were genotyped for COMT single nucleotide polymorphism rs4680 (Val158Met), using ARMS-PCR. Genotyping data has been analyzed using Chi square and the odd ratio has been calculated using SPSS.

Results

The most common polymorphism among Sudanese population is the Val\Met that is associated with moderate COMT activity it is a neutral genotype that presented by the three categories. Healthy individuals presented this genotype only. The polymorphism Met\Met presented only by fibromyalgia patients. This polymorphism is associated with low catecholamine-o-methyletrasnferease enzyme activity, as previous studies have shown. In contrast the polymorphism Val/Val presented only by rheumatoid patients.

Conclusion

The association between Met\Met polymorphism is in accordance with previous studies in other populations. The new findings is that the polymorphism Val\Val was significantly higher among rheumatoid patients. This may indicate that individuals with the GG polymorphism who have been exposed to physical trauma seem not develop fibromyalgia.

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Rufida Omer poster

INSILICO ANALYSIS OF SINGLE NUCLEUOTIDE POLYMORPHISM IN HUMAN 

DCDC2 GENE CAUSING DYSLEXIA DISEASE

 

Rufaida, O. S. Omer1*; Afra, M. Bakri1; Muna, A. M. Khaier2; Hind. A. Elnasri1

1*Corresponding author 

1-Department of Biochemistry and Molecular Biology, College of Veterinary Medicine, University of Bahri 

2- Department of Parasitology, College of Veterinary Medicine, University of Bahri 

 

Abstract:

Dobulecortin domain2 gene (DCDC2) which encodes for the doublecortin protein is located in chromosome 6p22.3. The doublecortin domain has been demonstrated to bind tubulin and enhance microtubule polymerization. Variants of the DCDC2 gene may affect the protein conformation and structure which might lead to learning disability (Dyslexia disease). The aim of this study was to analyze the genetic variation that can alter the expression and the function in DCDC2 gene using computational tools.

This study focused on the coding region. The total number of SNPs was obtained from dbSNP database. A total of 22 SNPs were found to be damaging by both SIFT and PolyPhen software.When using I-Mutant 3.0 software, 20 nsSNPs showed decreased protein stability while only 2 SNPs showed increase in protein stability.  This gene was found to co-expressed with 14 other genes and has a physical interaction with 1 gene using GeneMANIA software. A structural and functional analysis of ns SNPs was also studied by Project HOPE and Mupro software. Based on this work, four new ns SNPs are predicted to have pathological effect. Thus the most deleterious ns SNPs with an SNP IDs (rs375996594) was  proposed as the most important one. The others (rs372751993), – (rs36881196) and – (rs141060456) may also play an important role in investigation of dyslexia disease among patients.

Keywords: DCDC2, Dyslexia, Insilico Analysis, Reading Disability, Single Nucleotide Polymorphism (SNP)

 

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Hussam Ali

SCREENING FOR 3.7 AND 4.2 DELETION MUTATIONS IN SUDANESE PATIENTS SUSPECTED TO HAVE ALPHA THALASSAEMIA

Hussam Ali Osman1*, Sana Altahir Abdallah2

1Biotechnology Research Laboratory, School of Pharmacy, Ahafad University for Women, Omdurman, Sudan.

2 Department of Pathology, Faculty of Medicine, Alneelain University, Khartoum, Sudan.

Keywords: Alpha Thalassaemia, Homozygous, Heterozygous, Deletion mutations, GAP-PCR

Corresponding author: Hussam Ali Osman1*

Tel: +249-911000732   Fax: +249-187579111     Email: hussomco@gmail.com

 

Abstract:

Background: Alpha-thalassaemia is the genetic disorders, characterised by microcytic and hypochromic anaemia. Aim: The study aimed to screen the participant blood samples for the most common types of the alpha thalassaemia mutations in Africans (3.7 and 4.2 deletion mutations) and to correlate the findings with the CBC parameters. Methods: A cross sectional study targeted 98 patients of highly suspected to have alpha thalassemia. Results: Revealed of these 98 patients, 7 were carriers for the 3.7 deletion mutation and only one patient was 3.7 homozygous deletion mutation, while all samples were negative for the 4.2 deletion mutation. The 3.7 deletion mutation was found in a Sudanese tribes of Four, Hawsa and Rezagat, which originated from the West Africa. In the carriers of the 3.7 deletion mutation the RBCs and HCT were significantly increased “P-value <0.05”. The RBCs were 7.23±0.78×1012/L in adult males and 7.21±0.67×1012/L in adult females while in children were 5.07±0.87×1012/L. The MCV and MCH were clearly decreased, but the MCHC slightly decreased. The Hb levels revealed mild decrease without statistical significance “P-value ˃0.05” in adult males were 11.7±0.57 g/dl and 11.25±0.64 g/dl in adult females while in children were 11.6±2.95 g/dl. The Ferritin levels were normal and the RDW_CV% means were clearly increased. The quantitative Hb electrophoresis was normal in addition to the presence of many target cells in peripheral blood picture and no one of these carriers presence with clinical manifestations indicating for anaemia, but the homozygous 3.7 deletion mutation patient was anaemic and his basic haematological parameters were as follows RBCs 1.38×1012/L, Hb 4.99 g/dl, HCT 11%, MCV 79.7 fl, MCH 35.5 pg, MCHC 44.5 g/dl, RDW_CV 17.7% and his Ferritin level was1807 mg/dl and this elevation due to blood transfusion. Conclusion: Confirmed the presence of the alpha thalassaemia in Sudanese population for the 3.7 deletion mutation.

 

 

 

 

 

 

 

 

Name, title and affiliations of presenter:

 

Dr. Hussam Ali Osman (PhD)

Assistant Professor of Haematology

Ahfad University for Women

School of Pharmacy

Biotechnology Research Laboratory

 

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Fatima Hakam

KNOWLEDGE, ATTITUDE AND PRACTICE OF CONSANGUINEOUS MARRIAGE, IN SUDAN 2018.

Fatima A Elmugadam1, Liena ELsayed3, Haytham M Gorshi2, Almigdad HMohammed1, Murad Almak1, IsraaH Hussain1 Mohammed A.Farag1, Mohammed S.Tawar1, Elhami A Ahmed4, Almegdad S A1, Wadah O Awad1, Ahmed M Musa

Affiliation:

1- Khartoum University, Faculty of Medicine, Sudan

2- Institute of Endemic Diseases, Faculty of medicine, University of Khartoum, Sudan.

3- Department of Biochemistry, Faculty of Medicine, University of Khartoum, Sudan.

4- UNESCO chair in Bioethics, Faculty of Medicine, University of Khartoum, Sudan.

Aim: The study aimed to assess the knowledge, attitude and practice aspects on the relationship of consanguinity to negative health outcomes. Also, to explore the attitude towards premarital genetic testing.

 

Background: Consanguinity (intra-familial marriage) is a global health problem with various adverse health outcomes. As this practice increases homozygosity of recessive alleles, it results in higher risk of early mortality and morbidity. Although, Sudan has one of the highest rates of consanguinity exceeding 40-50%.

Methodology: Data was collected from 1089 participants. Study was conducted in 13 urban and semi urban areas from 8 different states, using convenience sampling, trained interviewers paid house visits. Sudanese residents, 18 years and above, irrespective of their socio-economic status, were interviewed based on a locally generated and tested questionnaire. Analysis was done using descriptive and inferential statistics.

Results: 518 (48%) of participants were females, 571(52%) were males. about 800(73%) were among 18-40 years’ age group. The majority of respondents 437(39%) were college graduates. 803(74%) agreed on the negative health consequences of consanguinity, while 150(14%) opposed and 136 (12%) said “I do not know”. Among the respondents, 696(64%) showed non-preference for consanguineous marriage, Most frequently due to the possible transmission of genetic diseases. Of the 393 (36%) that showed preference the most frequent reason was its contribution to the stability of marriage.  When asked if they were willing to undergo premarital genetic testing, 908(83%) of respondents agreed to take it.

Conclusion: in our study, the overall awareness towards the issue was moderately high. But the practice still persists also in high rates.  It is not a revolution needed against consanguineous marriage in Sudan, rather, we need more investigation and integration of public health genomics sector to build efficient community-based awareness programs.

Keywords: Consanguinity; awareness; attitude; Sudan.

 

Presenter: Fatima Abdelhakam Abdellatif, MBBS, Faculty of Medicine University of Khartoum.

 

 

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