25th February, 1971
Dear Dr. van Eys,
I was very pleased to receive your letter and we will be looking forward to hearing about pyruvate kinase deficiency and the X-linked thrombocytopenia. You will be interested to know that Bill Valentine is coming for Los Angeles to give the primary presentation on red cell enzymopathies.
If you can identify the heterozygote with reliability in the case of pyruvate kinase deficiency and have a large kindred available to you it should be possible to do linkage studies. We would be happy to do multiple marker traits here if you were to send blood samples to us. If you are interested, perhaps the first thing to do would be to send me a pedigree to see how many individuals, heterozygous and otherwise, there are available in the kindred for study.
Best regards.
Sincerely,
Victor A. McKusick, M.D.