Severe microcephaly

Gene: NRDC

Green List (high evidence)

Comment on list classification: There are 13 individuals reported with biallelic NRDC variants and microcephaly. While severity is not stated, this is a consistent feature in all patients. Hence, NRDC should be promoted to Green for Severe microcephaly, with MOI set to BIALLELIC, autosomal or pseudoautosomal.

Created: 27 Mar 2026, 2:42 p.m. | Last Modified: 27 Mar 2026, 2:42 p.m.

Panel Version: 8.41

PMID: 41734767 Pehlivan et al., 2026
Report of 14 individuals from nine unrelated families carrying homozygous NRDC pathogenic variants (some reported previously). Common clinical features include severe to profound developmental delay/intellectual disability (12/12), microcephaly (13/13), prematurity (5/13), lethality in the first 3 years of life (9/14), seizures (7/11), joint contractures (4/8), eye/visual abnormalities (5/7 - 3 with optic atrophy, 1 with nystagmus, and 1 case of visual inattentiveness), and abnormal brain imaging studies ranging from diffuse atrophy to lissencephaly (8/11). The identified variants include two splice, three frameshift, and three missense variants.

NRDC is not yet associated with a phenotype in OMIM (accessed 9th Mar 2026).
Sources: Literature

Created: 27 Mar 2026, 2:40 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
microcephaly, MONDO:0001149; neurodevelopmental disorder, MONDO:0700092; Optic neuropathy, HP:0001138

Publications

• 41734767