[Subtypes of specific language impairment in Spanish-speaking children: a cluster analysis of linguistic features]

Specific language impairment (SLI) can be viewed as a continuum with different subtypes depending on the combination of deficits and strengths in each of the components of linguistic behavior. AIM. To analyze the phenomenological profiles in a correlative series of Spanish children in order to facilitate their endophenotypic differentiation and the choice of strategies of intervention.

86 referred children, aged 4 to 9 years, with a mean non-verbal intelligence quotient of 93 (range 72-114) and accomplishing clinical criteria of SLI. Apart from clinical interview and neurological examination, a protocol of questionnaires and tests was used in all subjects in order to measure their formal (phonological, syntactic, lexical) and functional (semantic and pragmatic) linguistic abilities. A cluster analysis of variables was used in order to investigate SLI subtypes.

In the total sample, a 24% of whole series have a pure phonological expressive disorder. 55% of subjects have mixed receptive/expressive disorders; from these, the most pervasive subtype is due to verbal agnosia (11%), but more frequently observed subtypes affect syntax reception and expression combined to difficulties in phonological programming (36%) or in lexical retrieval (8%). Furthermore, 21% of the total sample present with difficulties in pragmatic use of language even if their formal linguistic abilities and non-verbal behavior are normal.

Our empirical approach confirms that the admitted SLI subtypes in international literature applies to Spanish-speaking children for endophenotyping and intervention-planning purposes.