A family study of coeliac disease

DQ2, DQ7 and DQ8 Distribution and Clinical Manifestations in Celiac Cases and Their First-Degree Relatives

HLA-linked genes are relevant to celiac disease (CD); the potential genetic differences present worldwide are not fully understood. Previous results suggest that the distribution of HLA-DQ2/DQ7/DQ8 in Chile may differ from that in Europe and North America. In celiac patients and their first-degree relatives (FDRS), we assessed their clinical, serological and histological characteristics, determined HLA-DQ2, HLA-DQ7 and HLA-DQ8 alleles and genotypes, and evaluated the relations between them. A total of 222 individuals were assessed (56 cases, 166 FDRs). 16.9% of FDRs were tTG positive; 53.6% of them showed overweight/obesity and 3% undernourishment; they spontaneously declared being asymptomatic, but detailed questioning revealed that 60.7% experienced symptoms, which had not been investigated. DQ2 was present in 53.9% and 43.9.0% of cases and FDRs (p < 0.05). The most frequent genotype distribution was DQ2/DQ7 (fr 0.392 (cases) and 0.248 (FDRs), respectively, p < 0.02). The next most common genotypes were HLA-DQ2/DQ8 (fr 0.236 in FDRs and 0.176 in cases, p < 0.05). 3.92% cases were not HLA-DQ2/DQ8 carriers. Among tTG positive FDRs, 57.4%, 22.3% and 20.2% carried DQ2, DQ7 and DQ8, respectively. In cases, 72.7% of the biopsies classified Marsh ≥ 3 carried at least one DQ2; 91.7% of DQ2/DQ2 and 88.3% of DQ2/DQ7 were Marsh ≥ 3. Thus, DQ2 frequency is lower than reported; the higher frequency found for DQ8 and DQ7 concur with recent publications from Argentine and Brazil. These results suggest that although CD may manifest clinically in ways similar to those described in other populations, some genetic peculiarities in this region deserve further study.

Influence of infant feeding and gluten intake on coeliac disease

OBJECTIVES

To study the impact of infant feeding habits and actual gluten intake on gluten induced enteropathy.

METHODS

A case-referent design, controlling for the HLA alleles conferring increased genetic risk, was used. All 164 siblings of 97 probands were investigated. Eighty five of the siblings, carrying the genes DQA1*0501-DQB1*02 conferring susceptibility for the disease, were investigated by interview, food recording, and taking a small intestinal biopsy sample. Eight cases of silent coeliac disease were found and these were compared with the 73 siblings in whom the diagnosis was excluded.

RESULTS

No statistically significant differences were found between cases and referents in terms of duration of breast feeding, age at introduction of cows' milk products, frequency of breast feeding after gluten introduction, and gluten consumption.

CONCLUSIONS

The studies factors may be of less importance for the development of gluten induced enteropathy.

A family study of coeliac disease

Thirteen of 141 cases (9 percent) of overt, biopsy proven coeliac disease had a definitely affected relative. The pattern of inheritance in these families is compatible with an incompletely penetrant autosomal dominant gene. There was a female preponderance in the adults and the sporadic cases, but not in the children or the familial cases. The series included a pair of concordant and probably monozygotic twins. The authors believe that coeliac disease, as defined at present, is a heterogeneous condition.