Role of genetic factor in specific language impairment : evidence from pedigree analysis

Abstract EN

Genetic factors account for much of the variance in linguistic abilities among people with language disorders and some of the variance in linguistic abilities among normal people.

There has been rapid growth of evidence indicating that genetics play an important role in the etiology of specific language impairment (SL1).

In the present study, pedigree analysis was performed for 25 probands of SLI in order to determine the possible mode of inheritance of such heritable disorder that can provide additional knowledge about the genotype of normal and affected individuals that may be helpful in genetic counseling.

The results revealed transmission pattern consistent with an autosomal mode of transmission.

The probability of the SLI in the offspring of an affected parent and normal spouse is approximately 0.5, exactly as would be predicted if a single dominant gene is implicated in the etiology.

The current state of the art of genetic studies related to SLI such as family aggregation studies, twin studies, adoption studies, pedigree analysis and molecular genetic studies was reviewed.

It appears that the genetics underlying this disorder are complex, involving several loci that interact with each other and the environment to produce an overall susceptibility to disease onset.