Association of CARD14 Single-Nucleotide Polymorphisms with Psoriasis.

Psoriasis is an immune-mediated chronic and painful disease characterized by red raised patches of inflamed skin that may have desquamation, silvery-white scales, itching and cracks. The susceptibility of developing psoriasis depends on multiple factors, with a complex interplay between genetic and environmental factors. Studies have suggested an association between autosomal dominant CARD14 (caspase recruitment domain-containing protein 14) gain-of-function mutations with the pathophysiology of psoriasis. In this study, non-synonymous single-nucleotide polymorphisms (nsSNPs) of CARD14 gene were assessed to determine their association with psoriasis in Pakistani population. A total of 123 subjects (63 patients with psoriasis and 60 normal controls) were included in this study. DNA was extracted from blood, and PCR analysis was performed followed by Sanger sequencing for 18 CARD14 specific nsSNPs (14 previously reported and the 4 most pathogenic nsSNPs identified using bioinformatics analysis). Among the 18 tested SNPs, only 2 nsSNP, rs2066965 (R547S) and rs34367357 (V585I), were found to be associated with psoriasis. Furthermore, rs2066965 heterozygous genotype was found to be more prevalent in patients with joint pain. Additionally, the 3D structure of CARD14 protein was predicted using alpha-fold2. NMSim web server was used to perform coarse grind simulations of wild-type CARD14 and two mutated structures. R547S increases protein flexibility, whereas V353I is shown to promote CARD14-induced NF-kappa B activation. This study confirms the association between two CARD14 nsSNPs, rs2066965 and rs34367357 with psoriasis in a Pakistani population, and could be helpful in identifying the role of CARD14 gene variants as potential genetic markers in patients with psoriasis.

Exome sequencing reveals the first intragenic deletion in ABCA5 underlying autosomal recessive hypertrichosis.

BACKGROUND: Hereditary hypertrichosis (HH) is characterized by excessive hair growth on various body areas, which is independent of the individual's age. This rare hair disorder has been classified by its origin (genetic or acquired), age of onset, breadth of hair distribution (universal or localized) and the affected body areas. HH is often linked to several additional congenital abnormalities involving teeth, heart and bones. Human HH is associated with heterozygous genomic duplications and deletions in the chromosomal region 17q24.2-q24.3, containing genes such as ABCA5, ABCA6, ABCA10 and MAP2K6. Recently, a homozygous splice-site variant in ABCA5 has been reported to cause autosomal recessive congenital generalized hypertrichosis terminalis (CGHT; OMIM 135400). AIM: To investigate the clinical and genetic basis of autosomal recessive hypertrichosis in a large consanguineous Pakistani family. METHODS: In the present study, we characterized a family of Pakistani origin segregating CGHT in an autosomal recessive pattern, using whole exome sequencing followed by Sanger sequencing. RESULTS: We identified a novel 2-bp intragenic deletion [NM_172232.4(ABCA5);c.977_978delAT] causing a frameshift variant (p.His326ArgfsTer5) in ABCA5. CONCLUSIONS: To our knowledge, this is the first intragenic deletion in ABCA5 underlying CGHT. The findings further validate the involvement of ABCA5 in hair development. The study will facilitate genetic counselling of families carrying CGHT-related features in Pakistani and other populations.

Homozygous variants of EDAR underlying hypohidrotic ectodermal dysplasia in three consanguineous families.

BACKGROUND: Hypohidrotic ectodermal dysplasia (HED) is a congenital anomaly characterized by hypohydrosis, hypotrichosis and hypodontia. Mutations in at least four genes (EDAR, EDARADD, WNT10A, TRAF6) have been reported to cause both autosomal recessive and autosomal dominant forms of HED. Mutations in two other genes (EDA and IKBKG) have been reported to cause X-linked HED. OBJECTIVES: To clinically characterize three consanguineous families (A-C) segregating with autosomal recessive HED and identify possible disease-causing variants of EDAR and EDARADD genes. MATERIALS AND METHODS: The genes, EDAR and EDARADD, were sequenced in Family A and C, and exome sequencing was performed in Family B. Additionally, in Family A and C, the effect of the identified variants was examined by analysis of EDAR mRNA, extracted from hair follicles from both affected and unaffected members. RESULTS: Sequence analysis revealed three possible disease-causing EDAR variants including a novel splice acceptor site variant (IVS3-1G > A) in Family A and two previously reported mutations (p.[Ala26Val], p.[Arg25*]) in the two other families. Previously, the nonsense variant p.(Arg25*) was reported only in the heterozygous state. Analysis of the RNA, extracted from hair follicles, revealed skipping of a downstream exon in EDAR and complete degradation of EDAR mRNA in affected members in family A and C, respectively. Computational modelling validated the pathogenic effect of the two variants identified in Family B and C. CONCLUSION: The three variants reported here expand the spectrum of EDAR mutations associated with HED which may further facilitate genetic counselling of families segregating with similar disorders in the Pakistani population.

ß2 Integrin Gene (ITGB2) mutation spectra in Pakistani families with leukocyte adhesion deficiency type 1 (LAD1).

Leukocyte adhesion deficiency I (LADI) is an autosomal recessive type of primary immunodeficiency characterized by occurrence of repeated bacterial infections, impaired pus formation and wound healing. Genetic variations in the ß-2 integrin subunit encoding gene ITGB2 have been implicated in causing the disorder. In the present study, we have investigated twelve patients presenting LAD1 features. After collecting clinical and family history, flow cytometry was used to determine levels of CD18 in the patients. Clinical history revealed that umbilical cord separation occurred mostly after 19 days in the patients. Recurrent skin infections were found in seven patients. Eight patients had at least one elder sibling who died due to repeated infections. All patients had marked neutrophilia with only 0.77% of neutrophils expressing CD18. Total 12 patients suffering from LAD1 were Sanger sequenced for ITGB2 gene. Five variants, including a novel p.(Cys286Phe) and four previously reported [p.(Gly273Arg), p.(Asp128Tyr), p.(Cys62*), IVS7 + 1G > A] were identified in 8 cases, while no pathogenic variant was observed in remaining four cases. This study represents the first comprehensive clinical and genetic characterization of LAD1 in Pakistani population. This will facilitate diagnosis and genetic counselling of patients with immunodeficiency disorders in Pakistani population.