[Discrimination between genetic factors in attention deficit].
OBJECTIVE
In order to elucidate the genetic and environmental components involved in the susceptibility to develop attention deficit hyperactivity disorder (ADHD), a complex segregation analysis on nuclear families (n = 53) ascertained from affected probands belonging to Medellín, in the Antioquian State, Colombia, was performed.


RESULTS
Models of cohort effect (non-inheritance), multifactorial, recessive major gene, non-major gene component and non-transmission of major gene were rejected. Contrarily, dominant and codominant major gene models and non-multifactorial component could not be rejected. Thus, the better model fitting the data was that of the major gene (dominant/codominant). This major gene explains more than 99.99% of the ADHD phenotypic variance (value of heritability in the mixed model equal to 0.007%), which permit to assume a low aport of the environmental component to the phenotype ADHD. Gene frequency of the major gene was 3% in the general population of Antioquia and its penetrance was closed to 30%.


CONCLUSIONS
Some cautions and aspects related to the bias of the interview and diagnosis of the parents are discussed.
Lopera
F
F
Programa de Neurociencias, Universidad de Antioquia, Colombia.
Palacio
L G
LG
Jiménez
I
I
Villegas
P
P
Puerta
I C
IC
Pineda
D
D
Jiménez
M
M
Arcos-Burgos
M
M
D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003469:Culture; D006801:Humans; D019683:Penetrance; D010641:Phenotype; D011569:Psychiatric Status Rating Scales; D013030:Spain
Discriminación de factores genéticos en el déficit de atención.