Search

Data on inflammatory bowel disease (IBD) phenotypes among the Arab population in Israel or in the neighboring Arab countries is scarce. We aimed to assess differences in disease phenotype among Arab and Jewish children living in Israel. We performed a retrospective chart review of pediatric IBD cases, which were diagnosed at the Schneider Children’s Medical Center and Ha’Emek Medical Center in Israel between 2000 and 2014. Demographic, clinical, and phenotypic variables were compared between Arabs and Jews from Eastern (Sephardic) and Western (Ashkenazi) origin. Seventy-one Arab children with IBD were compared with 165 Ashkenazi and 158 Sephardic Jewish children. Age and gender did not differ between groups. Sephardic and Ashkenazi Jewish Crohn’s disease (CD) patients had significantly more stenotic behavior (24 and 26 vs. 5%, p = 0.03) and less fistulzing perianal disease (15 and 11 vs. 31%, p = 0.014) compared with Arab patients. Arab children with ulcerative colitis (UC) had more severe disease at diagnosis compared to Sephardic and Ashkenazi Jews reflected by higher Pediatric UC Activity Index (45 vs. 35 and 35, respectively, p = 0.03). Arab patients had significantly lower proportion of anti-Saccharomyces cerevisiae antibodies positivity (in CD) and perinuclear anti-neutrophil cytoplasmic antibodies positivity (in UC) than both Sephardic and Ashkenazi Jewish children (23 vs. 53 and 65%, p = 0.002 and 35 vs. 60 and 75%, respectively, p = 0.002). Arab and Jewish children with IBD differ in disease characteristics and severity. Whether genetic or environmental factors are the cause for these differences is yet to be determined.

The relative contribution of immunological dysregulation and impaired epithelial barrier function to allergic diseases is still a matter of debate. Here we describe a new syndrome featuring severe dermatitis, multiple allergies and metabolic wasting (SAM syndrome) caused by homozygous mutations in DSG1. DSG1 encodes desmoglein 1, a major constituent of desmosomes, which connect the cell surface to the keratin cytoskeleton and play a crucial role in maintaining epidermal integrity and barrier function. SAM syndrome-causing mutations resulted in lack of membrane expression of DSG1, leading to loss of cell-cell adhesion. In addition, DSG1 deficiency was associated with increased expression of a number of genes encoding allergy-related cytokines. The deciphering of the pathogenesis of SAM syndrome substantiates the notion that allergy may result from a primary structural epidermal defect.