October 2, 1954

Dr. Otto Schales

Director of Chemical Research
Alton Oshsner Medical Foundation
3503 Prytania Street

New Orkeans, La/

Dear Dr. Schales,

Thank you for your interesting letter of September 27 on congenital
subluxation in German Shepherds. This is not a question to which T can
give you an offhand answer, as my specialty im in the genetics of other
organisms, but I will give the matter my attention at the earliest convenient
opportunity, during the next few weeks, I will be surprised if there is not
already some informative literature; if not, I will forward your inquiry to
other authopities, If the trait is fully recessive, it will not be an easy
matter to eradicate it, or predict when it will come up, unless very detailed
pedigrees of the ancestors and correlative lines are available. for a few
genetic diseases, however, the heterozygotes can be detected, or the means of
detection might be searched, fpr.

In any event, it would be wise to collect as mich pedigree information
as you conveniently can. Even if a similar defect has been described before,
it is not always possible to be sure of the identity of genetic etiology of
two similar diseases solely on the basis of pathological evidence, If you have
data on the issue of crosses between parents of which one or both 1s affected,
these would be the most valuable, If possible, the sex of the individuals should
be indicated, together with any other distinctions that might lead to the pos-
sible detection of the heterozygous "carriers" of the disease,

T can fully sympathize with the grief that such diseases can cause, It
is unfortanate that in the past, breeders of animals for show were so narrow-
minded in their aims in the breeding of “superior types, Probably cats have
suffered from this even more than dogs, In livestock breeding (for rather dif-
ferent ends, to be sure) the first necessary accomplishment was the substitution
of rational, quantitative measures of performahce for the artificial and unrealistic
standafds of the show ring,

Yours sincerely,

Joshua Lederberg
Professor of Genetics