Autism spectrum disorder (ASD) is a neurodevelopmental condition with symptoms that
affect the whole personality and all aspects of life. Although there is a high degree
of heterogeneity in both its etiology and its characteristic behavioral patterns,
the disorder is well-captured along the autistic triad. Currently, ASD status can
be confirmed following an assessment of behavioral features, but there is a growing
emphasis on conceptualizing autism as a spectrum, which allows for establishing a
diagnosis based on the level of support need, free of discrete categories. Since ASD
has a high genetic predominance, the number of genetic variations identified in the
background of the condition is increasing exponentially as genetic testing methods
are rapidly evolving. However, due to the huge amount of data to be analyzed, grouping
the different DNA variations is still challenging. Therefore, in the present review,
a multidimensional classification scheme was developed to accommodate most of the
currently known genetic variants associated with autism. Genetic variations have been
grouped according to six criteria (extent, time of onset, information content, frequency,
number of genes involved, inheritance pattern), which are themselves not discrete
categories, but form a coherent continuum in line with the autism spectrum approach.
