Beaker bytes
Flu shots for preschoolers?
Current policies recommend universal flu vaccination for children aged 6 to 23 months, and shots for older children only if they have high-risk medical conditions. But an analysis by Kenneth Mandl, MD, and John Brownstein, PhD, of the Children's Hospital Informatics Program, suggests that 3- and 4-year-olds drive flu epidemics and should also be considered for vaccination.
The researchers used real-time biosurveillance data on medical visits from 2000 to 2004 at five Boston-area healthcare settings (including Children's emergency department) and found that children aged 3 to 4 clearly led influenza epidemics, presenting with flu-like respiratory illness as early as late September. Children aged 0 to 2 began arriving a week or two later, while older children first arrived in October and adults in November.
Overall, flu-like illness in children under age 5 was the best predictor of pneumonia and influenza deaths in the general population. While visits by children aged 0 to 2 were most predictive of mortality, those of 3- and 4-year-olds followed close behind, suggesting that preschoolers, not just infants and toddlers, are important flu spreaders.
"These data make sense because preschools and daycares are hotbeds of infection," says Brownstein, lead author of the study, which was published in the October 1 issue of the American Journal of Epidemiology.
Rare disorder may open some eyes
A rare genetic syndrome discovered at Children's Hospital Boston causes impaired eye movement, but it also has implications that go far beyond the eye.
The mutated gene, HOXA1, is part of a large family of genes that govern early embryonic development; it drives the patterning of the head, face and brainstem. Until this study, it was assumed that two mutated copies of HOXA1 would be lethal, but graduate student Max Tischfield and neurologist Elizabeth Engle, MD, of the Program in Genomics, found people with double mutations from three different parts of the world.
Engle, a world expert in the genetics of eye-movement disorders, knew of some double-mutation Saudi Arabian patients with deafness and motor impairments in addition to a restricted horizontal gaze. A closer look revealed that many also had malformations of the internal carotid arteries, which supply blood to the brain, and some met criteria for autistic spectrum disorder. A Turkish patient in Engle's database had a similar pattern of symptoms; then, Engle recalled reading of a group of Native American children who also fit the picture. These children also had mental retardation, and some had heart defects.
Tischfield's DNA analysis pinpointed HOXA1 mutations in all three groups. He and Engle expect this discovery will spark further research: the heart and carotid-artery malformations suggest, for the first time, that HOXA1 is involved in early cardiovascular development, and the presence of mental retardation and autism suggests that HOXA1 mutations in the brainstem—which governs "lower" brain functions like eye movement—can also impair cognitive and behavioral function, thought to reside in the cerebrum and cerebellum. The study appeared in the September 11 online Nature Genetics.
