In any one family, some children might inherit a recessive gene, or all of them, or none of them; even if both of their parents are carriers the chances are still only one in four. Depending on the genetic match of the parents, the lists below show the likely characteristics that will be inherited by their children.
Dominant Traits Recessive traits
Brown eyes Green, grey, hazel or blue eyes
Dark hair Blonde or red hair
Normal vision Colour blindness
Full lips Thin lips
Freckles No freckles
The Weasley Factor
Though medical geneticists are generally uninterested in what children look like, they have worked out one gene code for appearance: the MC1R gene produces red hair and pale skin that's likely to burn because it doesn't have photo-protective melanin. Due to the rarity of this gene, some experts predict that natural red-heads will be no more within 50 years. Natural blondes could also be on the wane in the UK where only three per cent of the population are naturally blonde.
The language of the genes
Scientists at the Centre for Human Genetics in Oxford have identified the first gene known to be involved in the development of speech and language. It is believed this will lead to improved diagnosis of language disorders and other conditions, like autism. It had always been assumed there was a genetic basis to speech and language as it's acquired almost instinctively by children. The Oxford team got their breakthrough by studying three generations of a family affected by a rare language condition. Now they're working on tracking down the gene which predisposes children to dyslexia.
How big will he grow?
Everyone wants to know how tall their son or daughter will be, though most parents are more concerned about boys' height. There are many ways of predicting height - one way uses a complicated formula involving the combined heights of the parents. This prediction has a 68 per cent chance of being within two inches of his adult height. To try this method, visit www.pediatrics.about.com and write 'height prediction' in the search box. Another way is to simply double the height your child was aged two.
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