severe intellectual disability¹ which may inhibit detailed neurological assessment

The cognitive deficit in CLS males is significant, with IQ scores ranging from very low to moderate  (between 15 and 60), but clustering in the severely deficient range. Partington et al. (1988) found no evidence for intellectual deterioration with age, although it had been reported previously  (Coffin et al., 1966,  Procopis et al., 1972). There are rare instances of RSK2 mutations that do not produce the classical phenotype; in these cases, intellectual disability may be mild to moderate.

abnormal brain MRI findings, aka "white matter" disease

pleasant personality

Most people with CLS are generally happy and easygoing. Their temperament remains friendly throughout life and, despite their limited verbal abilities, their communication skills are good.

Female carriers may have a higher rate of psychiatric illness than that found in the general population. Six (8.8%) of 68 women (22 females with CLS, 38 heterozygotes, and eight 'affected' sisters) have had psychiatric diagnoses, including schizophrenia, bipolar disease, and 'psychosis' [reviewed in Hunter 2002].

Speech delays

development  is always affected but to variable degrees.

There are certain behaviors that may occur that overlap with some characteristics of autism:

	perseverative speech  - repeating the same phrases or questions over and over
	language delays
	general anxiety
	dislike of being touched
	severe temper tantrums, especially when required to change from a favorite activity to some other activity.
	emotional outbursts
	over- or undersensitivity to pain, no fear of danger
	Aggressive or self-injurious behavior issues. Click here for help with this issue.