February 16, 1971
Dear Dr. McKusick:
I am planning to attend the Fourth Annual Conference on the Clinical Delineation of the Birth Defects in June, 1971. I received your preliminary layout for the conference earlier this month with your request for suggestions for other topics.
My primary interest in attending the conference is one of information seeking.
However, we are actively engaged in investigating a large kindred with a high incidence of heterozygosity for pyruvate kinase deficiency. I will be pleased to have the opportunity to mention this informally if this were appropriate. In addition, we have the fortunate opportunity of studying a family with sex-linked hereditary thrombocytopenia.  Again, we will be glad if this is opportune to present the information we have on this family briefly.
I appreciate the opportunity to be present at this conference, and I will, of course, be glad to give any more information that is necessary,  in case you feel these suggestions are worthy of consideration.
Sincerely yours,
J. van Eys, M.D., Ph.D.