Co‐occurrence of birth defects and intellectual disability

Abstract

This study used population-based databases to ascertain birth defects and intellectual disability (ID), defined as full IQ < 70, in children born in Western Australia during 1980-99. Of the children surviving to 1 year (n = 474 285), 4.9% had birth defects and 1.3% ID. ID was identified in 7.9% of children with birth defects. After adjusting for sex, mother's age, race, parity, plurality, birthweight and gestational age the prevalence ratio (PR) [95% confidence interval (CI)] for ID in children with birth defects compared with those with no birth defects was 7.6 [7.2, 8.0]. Those with chromosomal anomalies comprised 3.2% of the group with birth defects. The percentage ID (and PR [95% CI]) in specific categories were: Down's syndrome 97% (84.5 [79.4, 90.0]), sex chromosome anomalies 30.3% (31.0 [23.8, 40.3]), other chromosomal anomalies 64.2% (54.2 [47.2, 62.3]). Birth defects were categorised according to system in the 96.8% of children with non-chromosomal anomalies. The percentage with ID (and PR [95% CI]) for birth defects in each system were: spina bifida 18.8 (16.7 [12.2, 23.0]); nervous (except spina bifida) 38.6 (33.4 [30.3, 36.9]); cardiovascular 4.2 (4.1 [3.5, 4.8]); gastro-intestinal 2.2 (2.0 [1.5, 2.7]); urogenital 2.6 (2.4 [2.0, 2.8]; musculo-skeletal 3.6 (4.0 [3.5, 4.6]); other non-chromosomal 7.0 (7.3 [6.5, 8.3]); and multiple systems 12.3 (10.2 [8.6, 12.2]). Birth defects were present in 30.2% of children with ID (27.7% of children with mild/moderate ID (IQ 40-69) and 54% of children with severe ID (IQ < 40)). Adjusted PRs for birth defects in children with any ID, mild/moderate ID and severe ID compared with children with normal intellectual function were 6.0 [5.8, 6.3], 5.5 [5.3, 5.8] and 10.5 [9.7, 11.4] respectively. The data are useful for those providing services for children with developmental disabilities especially for predicting family support and respite and accommodation requirements for children and adults with severe ID.

Prevalence of chronic diseases in adolescents with intellectual disability

“…Previous studies on youth with ID also found higher prevalence rates of a wide range of mental chronic diseases (Emerson & Hatton, 2007;Emerson, 2003;Magnusson & Saemundsen, 2001;Voigt et al, 2006) and a wide range of congenital malformations (Petterson et al, 2007) though. However, these studies did not separately report on adolescents, thus failing to recognize adolescence as a specific developmental stage.…”

“…2007a; Nielsen, Skov, & Jensen, 2007b;Nordin & Gillberg, 1996;Petterson, Bourke, Leonard, Jacoby, & Bower, 2007;Steffenburg, Gillberg, & Steffenburg, 1996;Stromme & Diseth, 2000;Stromme & Hagberg, 2000;Van Schrojenstein Lantmande Valk, van den Akker, Maaskant, & Haveman, 1997;Voigt, Barbaresi, Colligan, Weaver, & Katusic, 2006;Yeargin-Allsopp, Murphy, Cordero, Decoufle, & Hollowell, 1997;Zhang & Ji, 2005). However, only few studies have reported such prevalence rates of a wide range of chronic diseases associated with ID (Fernell, 1998;Stromme & Diseth, 2000;Stromme & Hagberg, 2000;Van Schrojenstein Lantman-de Valk et al, 1997).…”

“…However, only few studies have reported such prevalence rates of a wide range of chronic diseases associated with ID (Fernell, 1998;Stromme & Diseth, 2000;Stromme & Hagberg, 2000;Van Schrojenstein Lantman-de Valk et al, 1997). Moreover, only some studies compared their results with the prevalence rates of chronic diseases in the general population (Emerson & Hatton, 2007;Emerson, 2003;Magnusson & Saemundsen, 2001;Petterson et al, 2007;Voigt et al, 2006), and none of these studies reported prevalence rates of chronic diseases among ID-adolescents.…”

“…It is a time of life marked by physical, emotional, behavioural and social changes, but also by relatively high risks for the onset of (chronic) health problems (Patton & Viner, 2007;Sawyer et al, 2007;Turk, Graham, & Verhulst, 2007). Literature about young people with ID suggests that adolescents have a greater risk on chronic diseases compared to adolescents without ID (Cooper, Melville, & Morrison, 2004;Emerson & Hatton, 2007;Emerson, 2003;Jansen, Krol, Groothoff, & Post, 2004;Kolaitis, 2008;Magnusson & Saemundsen, 2001;Petterson et al, 2007;Van Schrojenstein Lantman-de Valk & Walsh, 2008;Voigt et al, 2006), but inclusive data on this are lacking.…”

Intellectual disability: definition, etiological factors, classification, diagnosis, treatment and prognosis

“…Millions of people worldwide have intellectual disability and prevalence is calculated to be 1 to 3% in developed countries. 1 In Mexico, according to INDESOL (National Social Development Institute) calculations, there are 2 925 000 persons with some type of intellectual disability. 2 In spite of this fact, knowledge of its causes is very limited and the etiological diagnosis in developed countries is almost always established as being a little less than half of the subjects affected.…”