Despite the common mechanism of haploinsufficiency, there is distinct phenotypic variability amongst patients. Although one third of patients are non-verbal, others can communicate with single words, while others can speak conversationally using 4-5 word sentences.
SYNGAP1-related intellectual disability
SYT1-associated neurodevelopmental disorder
MECP2 duplication syndrome
LMNA-related congenital muscular dystrophy
X-linked intellectual disability
X-linked spinal muscular atrophy type 2
Autosomal recessive spastic ataxia of Charlevoix-Saguenay
Foster Kennedy syndrome