Table 2. Psychological test results for the proband and his siblings.

Psychological parameters	Proband (8/IV)	Sibling 1 (7/IV)	Sibling 2 (9/IV)
Verbal ability	Low	Average	Above
Perceptual ability	Average	Above	Above
Full scale IQ	Low	Above	Above
Attention deficit	Yes	No	Ambiguous
Hyperactivity	Yes	No	Ambiguous
SLD	Yes	No	Ambiguous
Speech disorder	Yes	No	Yes
Autism	No	No	No

IQ, intelligence quotient; SLD, specific learning disabilities.