Characteristics of hydrocephalus expression in the LEW/Jms rat strain with inherited disease.
METHODS
The expression and severity of hydrocephalus was characterized in LEW/Jms rats with inherited hydrocephalus.


RESULTS
The frequency of overt disease (lethal) was 27.7%, but varied depending on breeding line. It increased to 31.5% when rats with mild disease were included. Most breeding pairs (48/51) produced hydrocephalic offspring with significantly more males than females affected. Some adult rats were also found to have mild (nonlethal) ventricular dilatation. When bred to Fisher F344 rats, 3% of the F(1) progeny had overt hydrocephalus, indicating that the trait is not recessive. Overt hydrocephalus was 9-20% in N(2) rats (F(1) rats x LEW/Jms). The frequency of hydrocephalus and the presence of an excess of hydrocephalic males, varied depending on the direction of the cross. Mild hydrocephalus in N(2) rats was 3.1%.


CONCLUSIONS
It is concluded that the inheritance of hydrocephalus in LEW/Jms strain is probably not mendelian recessive but may be semidominant or involve more than one gene and has a male bias indicating possible linkage to sex chromosomes.
Jones
Hazel C
HC
Department of Pharmacology and Therapeutics, University of Florida, P.O. Box 100267, Gainesville, FL 32610, USA. hjones@college.med.ufl.edu
Carter
Barbara J
BJ
Morel
Laurence
L
D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000254:growth & development / Q000473:pathology*; D001947:Breeding; D003433:Crosses, Genetic; D005260:Female; D006849:Hydrocephalus / Q000235:genetics* / Q000473:pathology; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D012720:Severity of Illness Index; D012737:Sex Factors