Table 2.

Developmental outcomes of the 4 patients with Schaaf-Yang syndrome.

	Patient #1	Patient #2	Patient #3	Patient #4
Age at most recent examination (Dec 2019)	38 months	6 months	47 months	36 months
Motor development
Head control	5 months	x	6 months	NA
Roll-over	9 months		7 months	NA
Sit alone with tripod	7 months		10 months	NA
Stand with support	11 months		14 months	NA
Standing independently	x		17 months	17 months
Walking independently	x		35 months	20 months
Language development
First word	x		36 months	24 months
First two-word sentence	x		x	x