An error by the NHS led to hundreds of families with African-Caribbean heritage being left unaware of whether their babies may be carriers of certain genetic blood disorders, the Guardian has learned. More than 800 families in Derbyshire were not sent the results of a heel prick test given to babies after birth, meaning they did not know whether their child was a carrier of a trait for sickle cell disease or for an unusual haemoglobin gene. The Guardian understands that the failure was uncovered in March this year, having gone unnoticed for 12 years, after a parent contacted the