Monday, March 31, 2008

Heredity: Stomach ulcers pass on from parents to offspring


March 31, 2008
By Syed Akbar
Stomach ulcers caused by the notorious germ that lives in the belly, Helicobacter pylori, are hereditary in nature. If parents suffer from gastric ulcers there's every likelihood of their children too inheriting the trouble.
The Centre for Liver Research and Diagnostics, Hyderabad, headed by eminent gastroenterologist Dr CM Habeebullah, has found that Helicobacter pylori transmits from parents to children. Both environmental and hereditary routes are suggested for the transmission from one generation to another in the family.
Says Dr Khaja Shakeel Ahmad of CLRD, "there's a relation between a history of ulcer and Helicobacter pylori infection in his or her family. This shows genetic factors play a role. The transmission is also due to common environmental factors that influence susceptibility to infection".
Helicobacter pylori infection is present in almost all patients with duodenal ulcers and gastric ulcers. The pathogenic role of Helicobacter pylori in peptic ulcer disease is well known. Up to 95 per cent of patients with duodenal ulcers, and 80 per cent of patients with gastric ulcers suffer from this infection.
The CLRD study was carried out in South Indian population, which is at high risk of stomach cancer. "We assessed the relationship between subjects with a history of gastric or duodenal ulcer and the risk of infection in their offspring with the help of
PCR assay targeting the 16S rRNA gene. The 16S rRNA gene is a highly specific target for amplification and has been previously of help in reclassifying the organism," Dr Khaja Shakeel Ahmad said.
The CLRD team interviewed the subjects referred to for upper gastrointestinal endoscopy at Deccan College of Medical Sciences and Research Center, Hyderabad, to find out whether their mother or father had been referred for endoscopy with the same symptoms or any history of ulcer.
The questionnaire sought details on risk factors for Helicobacter pylori infection, such as housing conditions, family demographics and socio-economic factors. "By 16S rRNA amplification, the status of Helicobacter pylori was confirmed," he said.
As many as 160 patients were enrolled in the study, of which 70 reported a parental history of ulcer, and 90 were without any history of ulcer. Of the 70 patients 14.2 per cent were Helicobacter pylori negative and 85.7 per cent were positive. In those with no family history of ulcer, the prevalence of the bacteria was 80 per cent and 20 per cent negative.
"The results propose the hypotheses that the transmission of Helicobacter may be influenced by the presence of ulcer or that the bacterial strains causing peptic ulcer may be more infective than other strains as published in earlier studies. This may be because of the relation between a history of ulcer and Helicobacter pylori infection in his or her family or due to common environmental or genetic factors that influence susceptibility to infection," he said.
Dr Khaja attributed the high prevalence of Helicobacter pylori infection in subjects with no family history of ulcer to their living conditions, socio-economic factors and cultural background.

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