Features include always present findings: Delayed CNS myelination, Short stature, Geographic atrophy, and Coarse facial features and others; and common findings: Biconcave vertebral bodies, Shrinkage of the cerebellum (cerebellar atrophy), Low muscle tone (hypotonia), and Ataxia and others.

NMNAT1 encodes nicotinamide nucleotide adenylyltransferase 1 (279 aa). Catalyzes the formation of NAD(+) from nicotinamide mononucleotide (NMN) and ATP. Can also use the deamidated form; nicotinic acid mononucleotide (NaMN) as substrate with the same efficiency. Highest expression in Cells Cultured fibroblasts (10.7 TPM) and Thyroid (7.5 TPM).

Spondyloepiphyseal dysplasia, sensorineural hearing loss, impaired intellectual development, and leber congenital amaurosis is associated with mutations in the NMNAT1 gene on chromosome 1.

The NMNAT1 protein participates in NMNAT1 transfers an adenylyl group from ATP to NAMN to yield NAAD pathway.

NMNAT1 is classified as a druggable target (Enzyme category) with score 0.0.

Genetic testing for NMNAT1 is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 23 always present features, 21 common features.