TABLE 2.

Two by two ANCOVA model (controlling for age) analysis results for outcome variable: Clinician reported intellectual disability (ID) severity, Vineland Adaptive Behavior Scales (VABS) composite score, aberrant behavior checklist adapted for fragile X (ABC_FX) total score, and Social Responsiveness Scale adapted for Fragile X (SRS_FX) total score, Fragile X Online Registry with Accessible Research Database, 2012–2019

	No methylation mosaicism		With methylation mosaicism		p	No size mosaicism		With size mosaicism		p
	N	Mean (± SD)	N	Mean (± SD)		N	Mean (± SD)	N	Mean (± SD)
Severity of IDa	341	3.82 (±0.74)	87	3.41 (±0.87)	<0.001	344	3.78 (±0.76)	84	3.52 (±0.84)	0.140
VABSb	130	55.19 (±15.60)	43	63.84 (±17.76)	0.002	139	55.88 (±16.21)	34	63.29 (±16.79)	0.481
ABCFXc	330	100.33 (±28.19)	84	96.43 (±28.98)	0.337	334	100.13 (±28.63)	80	97.06 (±27.22)	0.444
SRSFXd	280	68.77 (±20.70)	72	60.85 (±19.01)	0.020	279	68.49 (±20.44)	73	62.04 (±20.49)	0.120

^aSeverity of ID was categorized based on clinician report as 1 = no ID, 2 = borderline ID, 3 = mild ID, 4 = moderate ID, 5 = severe ID, and 6 = profound ID.

^bVABS measure adaptive skills, with higher scores indicating higher adaptive skills.

^cABC_FX measures 6 problem behaviors: irritability, social withdrawal, stereotypic behavior, hyperactivity/noncompliance, inappropriate speech, and social avoidance, with higher scores indicating more aberrant behavior.

^dSRS_FX measures social ability, with higher scores indicating more severe social impairment.