22q11.2 Deletion Syndrome, Special Needs, and Mathematics Learning

Characteristics

Chromosome 22q11.2 deletion syndrome (22q) is the most common genetic deletion syndrome with an estimated prevalence of between one in 3000 and 6000 births (e.g., Kobrynski and Sullivan 2007). It has only been detectable with 100% accuracy since 1992 using techniques such as the FISH test (fluorescence in situ hybridization). Prior to identification of a single associated deletion, the syndrome had been given a number of different labels according to the primary medical condition, for example, velocardiofacial syndrome, DiGeorge syndrome, Cayler syndrome, Shprintzen syndrome, and Catch 22.

The majority of individuals with 22q experience some degree of learning difficulty and generally show a marked imbalance in performance across different subtests within IQ batteries. Verbal IQ scores are usually significantly higher than performance IQ scores (e.g., Moss et al. 1999; Wang et al. 2007). The majority of children will receive some form of support at school although some...