Hostname: page-component-77c89778f8-sh8wx Total loading time: 0 Render date: 2024-07-17T05:51:08.775Z Has data issue: false hasContentIssue false

The Familial Aggregation of the Lesser Variant in Biological and Nonbiological Relatives of PDD Probands: a Family History Study

Published online by Cambridge University Press:  03 October 2000

Peter Szatmari
Affiliation:
McMaster University, Hamilton, Canada
Joanna E. MacLean
Affiliation:
McMaster University, Hamilton, Canada
Marshall B. Jones
Affiliation:
McMaster University, Hamilton, Canada
Susan E. Bryson
Affiliation:
McMaster University, Hamilton, Canada
Lonnie Zwaigenbaum
Affiliation:
McMaster University, Hamilton, Canada
Giampiero Bartolucci
Affiliation:
McMaster University, Hamilton, Canada
William J. Mahoney
Affiliation:
McMaster University, Hamilton, Canada
Larry Tuff
Affiliation:
McMaster University, Hamilton, Canada
Get access

Abstract

Objective: To determine the risk of the lesser variant (or PDD-like traits) in the biological and nonbiological second- and third-degree relatives of PDD probands using a screening questionnaire and to investigate the extent to which the risk of the lesser variant differs according to various characteristics of the proband. Method: The sample consists of a series of 34 nuclear families with 2 affected PDD children (multiplex, MPX), 44 families with a single PDD child (simplex, SPX), and 14 families who adopted a PDD child. Data on characteristics of the lesser variant in 1362 biological and 337 nonbiological second- and third-degree relatives were collected from parents by telephone interview and from several maternal and paternal relatives by questionnaire. Results: All components of the lesser variant were more common in biological relatives (BR) than nonbiological relatives (NBR), confirming the familial aggregation of the traits. Proband characteristics associated with an increased risk of the lesser variant in relatives were a higher level of functioning and coming from a MPX family. Conclusions: These findings on the familial aggregation of the lesser variant suggest that the genes for PDD also confer susceptibility to the lesser variant and that PDD may be a genetically heterogeneous disorder.

Type
Research Article
Copyright
© 2000 Association for Child Psychology and Psychiatry

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)