RAFAQAT ISHAQ

Mr. RAFAQAT ISHAQ

University of Maryland School of Medicine
+1

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 December 2019 in Genes
Verified
Journal Article
Open access
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MNMuhammad Noman
Muhammad Noman
RIRAFAQAT ISHAQ
RAFAQAT ISHAQ
SBShazia A. Bukhari
Shazia A. Bukhari
ZAZubair Ahmed
Zubair Ahmed
SRSaima Riazuddin
Saima Riazuddin
Hearing loss is a genetically heterogeneous disorder affecting approximately 360 million people worldwide and is among the most common sensorineural disorders. Here, we report a genetic analysis of seven large consanguineous families segregating prelingual sensorineural hearing loss. Whole-exome sequencing (WES) revealed seven different pathogenic variants segregating with hearing loss in these families, three novel variants (c.1204G>A, c.322G>T, and c.5587C>T) in TMPRSS3, ESRRB, and OTOF, and four previously reported variants (c.208C>T, c.6371G>A, c.226G>A, and c.494C>T) in LRTOMT, MYO15A, KCNE1, and LHFPL5, respectively. All identified variants had very low frequencies in the control databases and were predicted to have pathogenic effects on the encoded proteins. In addition to being familial, we also found intersibship locus heterogeneity in the evaluated families. The known pathogenic c.226C>T variant identified in KCNE1 only segregates with the hearing loss phenotype in a subset of affected members of the family GCNF21. This study further highlights the challenges of identifying disease-causing variants for highly heterogeneous disorders and reports the identification of three novel and four previously reported variants in seven known deafness genes.

31 July 2012 in International Journal of Dairy Technology
Verified
Journal Article
Closed access
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RIRAFAQAT ISHAQ
RAFAQAT ISHAQ
MSMuhammad Suleman
Muhammad Suleman
MRMuhammad Naeem Riaz
Muhammad Naeem Riaz
MYMuhammad Yousaf
Muhammad Yousaf
ASAbdullah Shah
Abdullah Shah
AGAbdul Ghafoor
Abdul Ghafoor

28 June 2014 in International Journal of Dairy Technology
Verified
Journal Article
Closed access
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AGAbdul Ghafoor
Abdul Ghafoor
MRMuhammad N Riaz
Muhammad N Riaz
AZAamer B Zahur
Aamer B Zahur
NANasir Abbas
Nasir Abbas
MYMuhammad Yousaf
Muhammad Yousaf
MSMuhammad Suleman
Muhammad Suleman

22 August 2020 in Genes
Verified
Journal Article
Open access
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SZsaba zafar
saba zafar
MSMOHSIN SHAHZAD
MOHSIN SHAHZAD
RIRAFAQAT ISHAQ
RAFAQAT ISHAQ
AYAyesha Yousaf
Ayesha Yousaf
RSRehan Sadiq Shaikh
Rehan Sadiq Shaikh
SRSaima Riazuddin
Saima Riazuddin
We report the underlying genetic causes of prelingual hearing loss (HL) segregating in eight large consanguineous families, ascertained from the Punjab province of Pakistan. Exome sequencing followed by segregation analysis revealed seven potentially pathogenic variants, including four novel alleles c.257G>A, c.6083A>C, c.89A>G, and c.1249A>G of CLPP, CDH23, COL4A5, and LARS2, respectively. We also identified three previously reported HL-causing variants (c.4528C>T, c.35delG, and c.1219T>C) of MYO15A, GJB2, and TMPRSS3 segregating in four families. All identified variants were either absent or had very low frequencies in the control databases. Our in silico analyses and 3-dimensional (3D) molecular modeling support the deleterious impact of these variants on the encoded proteins. Variants identified in MYO15A, GJB2, TMPRSS3, and CDH23 were classified as “pathogenic” or “likely pathogenic”, while the variants in CLPP and LARS2 fall in the category of “uncertain significance” based on the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) variant pathogenicity guidelines. This paper highlights the genetic diversity of hearing disorders in the Pakistani population and reports the identification of four novel mutations in four HL families.

26 February 2023 in Brain Sciences
Verified
Journal Article
Open access
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UHUmme Habiba
Umme Habiba
AMAafia malik
Aafia malik
GRGhazala Kaukab Raja
Ghazala Kaukab Raja
MMMuhammad Raza Memon
Muhammad Raza Memon
ANAsad Tameezud Din Nizami
Asad Tameezud Din Nizami
PSPakeeza Arzoo Shaiq
Pakeeza Arzoo Shaiq
Schizophrenia patients demonstrate variations in response to different therapies that are currently being used for the treatment of disorders, such as augmentation therapy (ECT or mood stabilizer) and combination therapy (with antipsychotics). These therapies are also used to treat schizophrenia patients in Pakistan; however, patients show poor overall response. Therefore, this study was conducted to investigate the association between the patients’ response to treatment and the use of antipsychotic agents, with variability in overall response, within different groups of patients. Methods: We conducted a retrospective study that included schizophrenia subjects (N = 200) belonging to different age groups, ethnicities, and regions from different outpatient and inpatient departments in psychiatric institutes located in different cities of Pakistan. These patients were assessed for their response to treatment therapies and categorized into four groups (non-responders (N-R), slow response (S-R), patients with relapse, and completely recovered patients (C-R)) according to their responses. Results: The final analysis included 200 subjects, of which 73.5% were males. Mean age was 34 ± 10 years. Percentage of N-R was 5%, S-R was 42%, patients with relapse were 24%, and C-R was 1.5%. The generalized linear regression model shows a significant association between medication response and age (p = 0.0231), age of onset (p = 0.0086), gender (p = 0.005), and marital status (p = 0.00169). Variability within the medication responses was a result of the treatment regime followed. Antipsychotic agents were significantly associated with the treatment response (p = 0.00258, F = 4.981) of the patients. Significant variation was also observed in the treatment response (p = 0.00128) of the patients that were given augmentation therapy as well as combination therapy. Conclusion: The data suggests proper monitoring of patients’ behavior in response to treatment therapies to implement tailored interventions. Despite several genetic studies supporting the heritability of schizophrenia, an insignificant association between characteristic features and family history might have been due to the limited sample size, suggesting collaborative work with massive sample sizes.

22 May 2023 in Genes
Verified
Journal Article
Open access
PDF file
RIRAFAQAT ISHAQ
RAFAQAT ISHAQ
MIMuhammad Ilyas
Muhammad Ilyas
UHUmme Habiba
Umme Habiba
MAMuhammad Noor ul Amin
Muhammad Noor ul Amin
SSSadia Saeed
Sadia Saeed
ZAZubair Ahmed
Zubair Ahmed
Vitiligo is an autoimmune complex pigmentation disease characterized by non-pigmented patches on the surface of the skin that affect approximately 0.5–2% population worldwide. The exact etiology is still unknown; however, vitiligo is hypothesized to be a multifactorial and genetically heterogeneous condition. Therefore, the current study is designed to investigate the anthropometric presentation and genetic spectrum of vitiligo in fifteen consanguineous Pakistani families. The clinical evaluation of participating individuals revealed varying degrees of disease severity, with 23 years as the average age of disease onset. The majority of the affected individuals had non-segmental vitiligo (NSV). Whole exome sequencing analysis revealed clustering of rare variants of known vitiligo-associated genes. For instance, in the affected individuals of family VF-12, we identified three novel rare variants of PTPN22 (c.1108C>A), NRROS (c.197C>T) and HERC2 (c.10969G>A) genes. All three variants replaced evolutionarily conserved amino acid residues in encoded proteins, which are predicted to impact the ionic interactions in the secondary structure. Although various in silico algorithms predicted low effect sizes for these variants individually, the clustering of them in affected individuals increases the polygenic burden of risk alleles. To our knowledge, this is the first study that highlights the complex etiology of vitiligo and genetic heterogeneity in multiplex consanguineous Pakistani families.