
the family history of spina bifida cystica
the family histories of 722 infants who
were born with spina bifida cystica were
studied.
the index cases were referred for sur-
gical treatment and were not selected in any
way from the genetic point of view.
intensive inquiries were made to ob-
tain a complete family pedigree, including
a prospective follow-up of siblings born after
the index case.
of 1,256 siblings 85 or 6.8% had gross
malformation of the central nervous system:
spina bifida cystica in 54, anencephaly in 22,
and uncomplicated hydrocephalus in 9.
of 306 children born after the index
case 25 (8%) or 1 in 12 were affected.
there was a progressive increase in
multiple cases in the family with increasing
family size.  in sibships of five or more, mul-
tiple cases occurred in 24.1%.
in 118 families cases of gross malfor-
mation of the central nervous system were
known to have occurred among members of
the family other than siblings.  cases oc-
curred in three generations.
it is possible that spina bifida cystica
might be a recessively inherited condition.
