PubMed Health⌕ Search

Biomedical subjects

J D Niswander

Publications and source records attributed to J D Niswander.

At least 19 recordsLinked to original sources
PubMed1977

Maternal effects in human cleft lip and palate.

To look for a persistent maternal effect of CL(P) and CP, 8,000 pedigrees were screened for half sibships, and data were pooled from 16 investigators. After excluding known genetic or cytogenetic diagnoses from the probands with facial clefts, a recurrence risk of .011 was obtained for CL(P) based upon 342 maternal half sibs. This was nearly identical to the risk of .014 based upon 210 paternal half sibs. CP proband frequencies of .004 for maternal half sibs and .009 for the paternal counterparts were also found. The lack of significant maternal effects in this data supports previously reported data from twin studies and from interracial crosses from Hawaii. The lack of maternal effect in human CL(P) and CP is in contrast to genetic data on clefting in mice.

Cleft Lip↗
PubMed1975

Polydactyly in the American Indian.

Polydactyly has an incidence in the American Indian twice that of Caucasians. A minimum estimate of this incidence is 2.40 per 1,000 live births. Preaxial type 1 has an incidence three to four times that reported for Caucasians or Negroes. The overall sex ratio in Indians is distorted with more males affected than females. The preaxial type 1 anomaly has a strong predilection for the hands and always is unilateral in contrast to postaxial type B where more than one-half are bilateral. The evidence to date, consisting of varying incidences of specific types of polydactyly among American whites, Negroes, and Indians in varying enviroments, suggests different gene-frequencies for polydactyly in each population. The incidence in Indians with 50% Caucasian admixture suggests that the factors controlling polydactyly are in large part genetically determined. Family studies and twin studies reported elsewhere offer no clear-cut genetic model which explains the highly variable gene frequencies.

Congenital Abnormalities↗