الفهرس 
Aim of The WorkOnly 14 pages are availabe for public view
 |  | from | 110 |  |  |
| | | from | 110 | | |
Abstract
Vitiligo is a common acquired disorder in which depigmented
skin results from destruction of melanocytes. Vitiligo is affecting
about 0.5%-1% of the population. It has a major impact on patients’
quality of life (QOL), especially in younger patients. The pathogenesis
of vitiligo is under debate and has been allocated to oxidative stress,
autoimmune causes, or sympathetic neurogenic disturbance. Vitiligo
is appeared to be transmitted genetically in a polygenic/multifactorial
manner.
Interferon-induced helicase (IFIH1), also called melanomadifferentiation-
associated gene 5 (MDA-5), is a locus in the innate
immunity viral RNA receptor gene region on chromosome (2q24.3)
(Gene ID: 64135). Interferon-induced helicase has been reported to be
associated with several autoimmune diseases such as Type 1 diabetes
mellitus, Graves’ disease, multiple sclerosis, psoriasis, and possibly
lupus erythematosus. All missense variants of IFIH1, i.e. rs1990760
(A946T), rs3747517 (H843R), and rs35667974 (l923V), showed
association with vitiligo in the independent replication study and the
former two showed associations in all three genome-wide association
studies.
This work aimed to study the role of IFIH1 gene polymorphism
(rs1990760) in vitiligo and to correlate the results with the available
clinical data. All patients were selected from Outpatient Clinic of
Dermatology, Andrology & STDs, Menoufia University Hospital
during the period study from August 2018 to September 2019.
This case control study was conducted on a total number of 100
subjects. These included 50 patients with different clinical types of
Summary
76
non-segmental vitiligo and 50 age and gender matched healthy
subjects as a control group. Patients were 21 (42%) males and 29
(58%) females with a male: female ratio of 1: 1.38 Their age ranged
from 12 – 65 years with 33.68±16.644 years as a mean ± SD value.
Control subjects were 23 (46%) males and 27 (54%) females with a
male: female ratio of 1: 1.17 Their age ranged from 17 – 63 years with
33.84 ±11.79 years as a mean ± SD value.
Onset of the disease was gradual in 36 (72 %) cases, while 14
(28%) cases had sudden onset vitiligo. Course of the disease was
progressive in 36 (72%) cases and was stationary in 14 (28%) cases.
Duration of the disease ranged from half year (6 months) to 7 years
with 1.78 ± 1.36 as a mean ± SD value. Family history of vitiligo was
positive in 7 (14%) cases and was negative in 43 (86 %) cases.
Regarding site of affection, lower limbs were affected in 12 (24%)
cases, back & trunck were affected in 14 (28%) cases, face &neck
were affected in 14 (28%) cases and upper limbs were affected in 10
(20%) cases. Spontaneous pigmentation was present in 4 (8%) cases.
Mucosal affection was present in 7 (14%) cases. Leucotrichia was
present in 6 (12%) cases. Koebnerization was present in 17 (34%)
cases.
Regarding type of non-segmental vitiligo; 14 (28%) cases were
with generalized vitiligo, 13 (26%) cases had acrofacial vitiligo, 12
(24%) cases were with focal vitiligo and 11 (22%) cases were with
universal vitiligo. VASI score ranged from 3-50 with 16.78±10.545 as
mean ±SD and VIDA score ranged from -1 – 4 with 2.08±1.576 as
mean ±SD.
Summary
77
There was statistically significant difference between cases and
controls regarding IFIH 1 genotypes (X2 = 35.825, P-value < 0.001)
and IFIH 1 alleles (X2 = 42.275, P-value <0.001).
There was statistically significant relationship between IFIH 1
genotypes and onset of the disease, mucosal affection, and type of
non-segmental vitiligo (P-value 0.005, 0.001, <0.001 respectively).
Regarding clinical data; There was statistically significant
relationship between IFIH 1 genotypes and onset of the disease,
mucosal affection, and type of non-segmental vitiligo (P-value 0.002,
<0.001, 0.005 respectively).
There was statistically significant positive correlation between
VASI score and duration of the disease in years in (P-value <0.001)
and There was no significant statistical correlation between VASI
score and age in years of the studied cases in years (P-value <0.001).