An unusual cause of non-5q spinal muscular atrophy: DYNCH1-related disease

Case presentation: This is a five-year-old boy, admitted with global development delay associated limb deformities. He was born prematurely at 35 weeks, by cesarean delivery due to pelvic presentation. During pregnancy, the mother noticed reduced fetal movements, and birth, neonatal resuscitation hospitalization required. congenital arthrogryposis (CA), thumbs in bilateral adduction, restricted plantar movement, hypotonia, facial dysmorphisms. Later, behavioral cognitive changes became evident, leading diagnosis of autism spectrum disorder. Laboratorial work-up revealed mild CPK elevation. Genetic testing identified heterozygous DYNCH1 pathogenic variant (p.Arg1201Ser), confirming Spinal Muscular Atrophy Lower Extremity - predominant (SMALED – OMIM: 158600).