Abstract We aimed to characterize the clinical spectrum of patients diagnosed with SRD5A3-CDG, a subtype of congenital disorders of glycosylation (CDG) due to variants in the steroid 5a-reductase type 3 (SRD5A3) gene. It presents with multi-systemic involvement including neurological disability, dermatologic abnormalities, and ophthalmological defects. We conducted a cross-sectional study of children (n=6, ages 4-16 years) with a confirmed diagnosis of SRD5A3-CDG (c.57G>A, p.W19X). Families completed a detailed medical history questionnaire, two quality of life measures, and an adaptive behavior scale. Prevalent clinical features in our cohort included visual impairment (6/6), developmental delay (6/6), nystagmus (5/6), retinal dystrophy (4/6), and hypotonia (3/6). The Vineland Adaptive Behavior Scales demonstrated deficits across all functional domains (Composite Mean 36.17 ± 26.88), although one child did not show significant deficits. The QI-Disability Form demonstrated a mean total score of 64.8 (±12.7), and the PedsQL-Family Impact Module demonstrated a mean total score of 56.5 (±31.5). Vineland composite scores did not correlate with levels of disability captured by the QI-Disability Form (Pearson Correlation range -0.63 to +0.69, p>0.05 on all subscales). Ultimately, despite genotypic homogeneity, there is notable variability in adaptive functioning and quality of life among affected children that does not correlate with age. SRD5A3CDG, SRD5A3CDG SRDACDG SRD5A3 CDG, CDG SRD A (CDG 5areductase areductase 5a reductase SRDA (SRD5A3 gene multisystemic multi systemic abnormalities defects crosssectional cross sectional n=6, n6 n 6 (n=6 416 4 16 4-1 years c.57G>A, c57GA cGA c 57G G (c.57G>A p.W19X. pW19X pWX p.W19X . p W19X W X p.W19X) questionnaire measures scale 6/6, 66 6/6 , (6/6) 5/6, 56 5/6 5 (5/6) 4/6, 46 4/6 (4/6) 3/6. 36 3/6 (3/6) Composite 3617 17 36.1 26.88, 2688 26.88 26 88 26.88) QIDisability QI Disability 648 64 8 64. ±12.7, 127 ±12.7 12 7 (±12.7) PedsQLFamily PedsQL Family 565 56. ±31.5. 315 ±31.5 31 (±31.5) Pearson 0.63 063 0 63 -0.6 069 69 +0.69 p005 05 p>0.0 subscales. subscales subscales) Ultimately homogeneity age SRD5A (SRD5A n=6 (n= 41 1 4- c.57G>A GA pW WX 6/ (6/6 5/ (5/6 4/ (4/6 3/ (3/6 361 36. 268 26.8 2 ±12. (±12.7 ±31. (±31.5 0.6 06 -0. +0.6 p00 p>0. n= (n (6/ (5/ (4/ (3/ 26. ±12 (±12. ±31 (±31. 0. -0 +0. p0 p>0 (6 (5 (4 (3 ±1 (±12 ±3 (±31 - +0 p> ( (±1 (±3 + (±