Fetal genes are thought to determine more than half of population variance in birthweight and paternal genes make a significant contribution. Data from all singleton births in Norway between 1967 and 1998 (

) show a 6.4% risk of low birth weight for the first child if the father was of low birthweight but a 3.4% risk if the father's birth weight was above 4000 g. (The same risks with regard to maternal birthweight were 9.3% and 2.2%). With both parents of low birthweight there was an eightfold increase in risk of low birth weight in the child compared with the risk with both parents weighing over 4000 g. Birth weight correlations were 0.226 for mother-child and 0.126 for father-child.

A study in the eight counties of the former Anglia and Oxford Health Region (

) has given a population prevalence for Prader-Willi syndrome of 1 in 52 000 but a male excess (55 males, 33 females, 8 sex unknown) suggests that female cases may have been missed and the true prevalence is probably around 1 in 45 000. The birth incidence was estimated to be at least 1 in 29 000 (possibly 1 in 20 000) and the estimated mortality rate around 3% per year across all age groups or 7% per year above the age of 30 years. (The overall mortality rate in England and Wales is around 1% per year).

Breastfeeding protects against childhood asthma especially when there is asthma in the family. A systematic review (

) of 12 published studies (8183 subjects) has given odds ratios for the development of childhood asthma in children exclusively breastfed during the first 3 months of 0.73 overall and 0.52 when there was a family history of atopy.

The finding of a triangular or tubular echogenic density just cranial to the portal vein bifurcation on ultrasound imaging in an infant with cholestatic jaundice has been called the triangular cord (TC) sign and is strongly suggestive of biliary atresia. In a recent study (

) 25 of 65 infants with prolonged conjugated hyperbilirubinaemia had the TC sign and all 25 proved to have biliary atresia. Of the other 40 infants, 31 had neonatal hepatitis, six had paucity of intrahepatic bile ducts, and three had alpha-1-antitrypsin deficiency. It is suggested that infants with the TC sign should have intraoperative cholangiography to confirm the diagnosis of biliary atresia and percutaneous liver biopsy should be reserved for those with no TC sign. The sign arises from fibrous remnants at the porta hepatis.

Living in very poor conditions in institutions permanently damages some, but not all, children. A group of 165 children from Romania who were adopted in the UK before the age of 42 months has been compared with 52 children born in the UK and adopted in infancy (

). Almost all of the Romanian children had lived in institutions where conditions were described as “extremely bad”, and many were severely underweight and developmentally impaired on arrival in the UK. None of the UK children suffered in this way. Examinations at ages 4 and 6 years showed a pattern of attachment problems, inattention, overactivity, quasi-autistic behaviour, and cognitive impairment in the institutionally deprived children. Emotional difficulties, peer relationship problems, and conduct problems were not more frequent in the Romanian children. Some (around 20%) of the children who spent a long time in institutions seemed unscarred.

Because influenza causes considerable morbidity in children it has been suggested that the indications for influenza vaccination might be expanded and some have considered universal vaccination. Both inactivated (intramuscular) and cold-adapted live attenuated (intranasal) vaccines are effective in children (

) and approval of the intranasal vaccine in the USA is expected. This trivalent vaccine (containing the two influenza A strains and the B strain) has 90% efficacy against both influenza A and influenza B viruses (see editorial, ibid: 731–2). Widespread vaccination of children would be expected to protect older people as well.

Because of concern about the possible adverse consequences of long-term treatment of children with stimulant drugs such as methylphenidate, the parents of American children with attention deficit/hyperactivity disorder (ADHD) often turn to complementary or alternative medicine. One treatment widely available consists of dietary supplementation with docosahexanoic acid (DHA) but a randomised, placebo-controlled trial (

) has given negative results. Plasma phospholipid DHA content increased significantly in the treated group but there were no significant differences between groups on tests of inattention and impulsivity or on behaviour ratings by the parents.

Reports from Oxford (

) and Boston, Massachusetts (

) have again drawn attention to the unsatisfactory results of diabetes treatment In the Oxford cohort, aged 11–18 years at baseline, 25% of males and 38% of females had developed diabetic complications 8 years later. In Boston 300 patients aged 7–16 years were followed up for 1 year. The rate of hospital admission was more than three times that in children and adolescents without diabetes. The American workers stress the importance of frequent blood glucose monitoring and diabetes control while the British report emphasises the importance of tackling behaviour problems in adolescence.

Both physical and mental problems are common in the children of homeless families. A study of families in supported temporary housing in Dublin (

) included 14 mothers, 2 fathers, and 31 children. Four of the mothers and 12 of the children had significant psychiatric problems. Fourteen children had externalising problems in the “deviant” range and nine had internalising problems in the “clinical” range. Eleven of the 14 families had at least one child with significant problems on the Child Behaviour Checklist and ten of the mothers had critical scores on the Parenting Stress Index. They commonly reported being dominated by their children's needs and demands and felt the lack of support from the father.

Publicised violence may induce threats of imitation. In the Columbine High School massacre of April 1999 two students in Colorado shot dead 13 other children and then killed themselves. In Pennsylvania (

) there were 354 recorded threats of school violence in the 50 days after the massacre. The threats peaked on days 8, 9, and 10 with a gradual increase and decrease before and after those days. These authors give guidance to media editors on the reporting of major violence in a way that may minimise the likelihood of copycat events or threats.