Motivation, learning physical

A 10-year-old boy is referred to the physician because of learning problems and a lack of motivation in school. His family history is unremarkable. Physical examination is normal except for single palmar creases of the hands and curved fifth fingers (clinodactyly). The physician decides to order a karyotype. Which of the lollowing indications for obtaining a karyotype "would best explain the physician s decision in this case ... 

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