Apolipoprotein B polymorphism and altered apolipoprotein B and low density lipoprotein cholesterol concentrations in Finnish children.

169 oscopy, false positive results are not uncommon with double contrast radiology, and up to 29% of polyps may be missed, although this figure falls to under 10% for polyps over 1 cm in diameter.'3 The presence of diverticular disease makes the diagnosis of associated lesions more difficult,'0 14 some authorities recommending that colonoscopy should be performed in all patients with symptomatic diverticular disease. 14 Another important group comprises patients with overt or occult rectal bleeding with no cause found on rigid sigmoidoscopy or barium examination: lesions may be shown in 27-81% of such cases, including tumours in 3-1 1%.4 15 Accurate cost comparisons in our hospitals are difficult to make, but the greater necessity for colonoscopy after an initial barium study would suggest that a policy of performing endoscopy initially is likely to work out less costly. For this reason and for reasons of accuracy and expediency and to avoid multiple investigations total colonoscopy may be the preferred initial investigation for those with suspected colonic disease. We have shown that radiology is not a prerequisite for adequate colonoscopic examination. We thank Professor 0 James and Dr R Lendrum for allowing us to include their patients in the study. SHORT REPORTS Apolipoprotein B polymorphism and altered apolipoprotein B and low density lipoprotein cholesterol concentrations in Finnish children With a monoclonal antibody we studied the relation between genetic variation in apolipoprotein B and serum concentrations of lipoprotein cholesterol and apolipoprotein B. The polymorphism detected by this antibody (MB-19) is identical to the Ag(c/g) polymorphism, one offive allelic variations described by Butler et al in the review by Tikkanen.' Antibody MB-19 distinguishes among three apolipoprotein B allotypes (immuno-phenotypes) encoded by the two allelic genes apoB(c) and apoB(g). Because of codominant transmission genotypes may be inferred from allotypes. We report an association between apoB(c) and serum concentrations of apolipoprotein B and low density lipoprotein cholesterol in Finnish children. Serum samples were obtained from 513 children who participated in an ongoing multicentre study on atherosclerosis precursors.2 The children were randomly selected from major cities and rural areas representing different parts of the country. Concentrations of serum lipids and low density lipoprotein and high density lipoprotein cholesterol and body mass index (kg/M2) were determined2 at the beginning of the study (1980), when the children were 9 years old. Serum apolipoprotein B concentrations were determined and allotypes assayed' in frozen serum that had been stored at-20°C …