Hereditary dyslipidemias and combined risk factors in children with a family history of premature coronary artery disease

AIM

Schoolchildren aged 10-11 with a family history of premature coronary artery disease (CAD), were examined in order to identify children with genetically determined dyslipidemias and a combination of risk factors.

METHODS

A total of 4000 questionnaires were distributed by the school; 55% of the families answered and returned the questionnaire. Blood lipids, apolipoprotein B, and Lp(a) lipoprotein were analysed in high risk children and their parents.

RESULTS

A family history of premature CAD in parents or grandparents was identified in 208 families; 175 agreed to take part in a clinical examination and laboratory tests. Normal blood lipid tests were found in 89 children. Another 48 had an isolated increase of Lp(a) lipoprotein of minor clinical importance. Of the remaining 38 children, 23 had non-hereditary abnormalities of low (LDL) or high density lipoprotein (HDL) cholesterol or apolipoprotein B. Fifteen children were suspected to have genetically determined dyslipidemias or a combination of risk factors: in four, possible familial hypercholesterolaemia (FH); in five, possible familial combined hyperlipidaemia; in three, hereditary low HDL cholesterol; and in three a combination of high LDL cholesterol and Lp(a) lipoprotein concentrations. In addition, possible FH was detected in eight of the parents.

CONCLUSION

It is worthwhile asking parents about the occurrence of premature CAD among their child's closest relatives.

Apolipoprotein A-I:B ratio and B screening: a preliminary study of 10- and 11-year-old children

The apolipoprotein (apo) A-I:B ratio and the apo B concentration were determined by radial immunodiffusion in dried blood spot samples from 1,767 10- and 11-year-old children. Children with either apo A-I:B ratios below the first percentile or apo B levels above the 99th were recalled and plasma lipid and apolipoprotein profiles were determined for both children and parents. Of 17 children (one family was lost to follow-up) recalled due to abnormal apo A-I:B ratios, apo B levels were above the 95th percentile in 13 children, and of 18 children with abnormal apo B screening levels (three of them also had abnormal apo A-I:B ratios), the plasma apo B level was elevated in 13 children. The 23 children with abnormal blood lipid and/or apolipoprotein concentrations were divided into two main groups: (a) children with type IIa hyperlipoproteinemia and (b) children with hyperapo B lipoproteinemia (hyperapo B) and normal blood lipid levels. Twelve children had the type IIa pattern. Five children likely had familial hypercholesterolemia (FH), the other seven children may have hypercholesterolemia due to obesity or environmental factors. Eleven children had the hyperapo B abnormality. In four children, the elevated apo B level probably was an indication of the occurrence of familial combined hypercholesterolemia (FCH) in the family. Of the remaining seven hyperapo B children, three children also had a parent with hyperapo B and a fourth family suffered from obesity.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperlipidemia in school children with family histories of premature coronary heart disease

Children starting their schooling were given a questionnaire asking about the occurrence of premature (before 50 years of age in men, 55 years in women) coronary heart disease (CHD) in first degree relatives. 1,920 of 2,069 questionnaires were answered, 140 of the 7-year-old children were reported to have a first degree relative with premature CHD, 84 of these 140 families agreed to participate in our study. In 79 of the 84 families both the child and the parent at 'high risk' were tested. In the initial test 19 of 84 children had total cholesterol (TC) levels above the 95th percentile (greater than 5.35 mmol/l). In the repeat test 12 of the 19 TC tests remained abnormal and all 12 also had LDL-cholesterol (LDL-C) levels above the 95th percentile (greater than 3.40 mmol/l). None had abnormal HDL-cholesterol or triglyceride levels. Among the high risk parents, 12 of 79 had abnormal initial blood lipid tests. In the repeat test 10 parents had both TC and LDL-C levels above the 95th percentile. In five families both the child and the parent had abnormal TC and LDL-C levels. In conclusion, a considerable proportion of children and parents with family histories of premature CHD have TC and LDL-C concentrations above the 95th percentile (in the present study, about 40 individuals in 140 high-risk families, if the parent and child considered at high risk all had agreed to participate). Prevention of heart disease should begin in childhood when patterns of life-style are developed. Identification by obtained family histories as in the current study may be a method of choice.