These are a group of disorders causing a problem with calcium metabolism. Only PPHP type 1b is truly an imprinting disorder. It is characterised by:
This sometimes causes hypocalcaemia (low blood calcium) and high blood phosphate. This can cause low energy, muscle cramps, twitches and thinning of the bones. However this is not always the case and is very variable.
Variable methylation defects on chromosome 20. Sometimes this is associated with a small deletion on chromosome 20 and this type can be inherited through the generations.
We would strongly recommend taking blood or DNA from both parents as well as the child, to establish the diagnosis more rapidly.
Send details on our request form for imprinting disorders. These include:
Any other clinical features
When taking samples you should get written consent for the testing - as with any genetic test. Where should the sample be sent?
Please email us before sending samples djgm@soton.ac.uk
The sample should be sent to:
Dr Deborah Mackay,
Lecturer in Human Genetics
Wessex Regional Genetics Laboratory,
Salisbury Health Care Trust
Salisbury
Wiltshire
SP2 8BJ
01722 425048 or 01722429012
And clinical details can be discussed with
Dr Karen Temple
Prof of Medical Genetics
and Honorary Consultant in Clinical Genetics
Academic Unit of Genetic Medicine
Princess Anne Hospital
Coxford Road
Southampton
SO16 5YA
ikt@soton.ac.uk
tel 02380 796625
For more information on genetic testing please look at the genetic testing section on this website.