Subsequently, we have diagnosed many other cases both in infants and older children and are the main diagnostic and clinical centre in the United Kingdom.
Preliminary diagnosis is based on an abnormal serum transferrin pattern.
If there is a deficiency of phosphomannomutase we carry out mutation analysis in the PMM2 gene. Thus we can offer a complete diagnostic service for CDGS 1A patients and clinical support and genetic counselling for families. We are looking at this anomaly. Phosphomannomutase can be measured both directly in a chorionic villus sample taken at about 10 weeks and in cultured cells obtained after amniocentesis at about 16 weeks gestation. Interestingly, none of them has a deficiency of the other documented enzymic deficiency causing CDGS, phosphomannose isomerase, either.