“Nonsyndromic Congenital Retinal Nonattachment”, Victor McKusick, Mendelian Inheritance in Man, 1966. (ATOH7) icd10=Q14.1

ATOH7 (atonal homolog 7) is a well-established retinal gene at chromosome 10q21.3 that is directly linked to Nonsyndromic Congenital Retinal Nonattachment (NCRNA) and related eye malformations.

🧬 ATOH7 — Basic Facts
Full name: Atonal homolog 7
Gene type: Protein-coding, basic helix-loop-helix (bHLH) transcription factor
Location: Chromosome 10q21.3
Function: Critical for early retinal development, especially the differentiation of retinal ganglion cells (RGCs), which are the first neurons formed in the retina and essential for optic nerve formation. 

👁️ ATOH7 and Retinal Nonattachment
Association with NCRNA: Mutations in ATOH7 have been identified as a cause of nonsyndromic congenital retinal nonattachment (NCRNA), a form of severe congenital retinal detachment where the retina fails to attach properly during development.

These mutations can be coding variants or regulatory deletions upstream of ATOH7 that disrupt its expression.

A homozygous deletion of remote regulatory elements’ upstream of ATOH7 was shown to segregate with NCRNA in affected families — highlighting that both structural gene mutations and regulatory region disruptions can underlie this disease.

🧠 Mechanism
ATOH7 is necessary for retinal ganglion cell (RGC) specification. Without enough functional ATOH7, RGCs fail to form normally, leading to:
Reduced trophic signaling to developing retinal vasculature
Failure of retinal vascular and tissue development
Secondary effects like persistent fetal vasculature, retinal nonattachment, or persistent hyperplastic primary vitreous (PHPV)
— these manifestations overlap clinically and genetically.

🧬 Clinical Spectrum
Mutations in ATOH7 are associated with a range of overlapping ocular phenotypes, including:
Nonsyndromic congenital retinal nonattachment (NCRNA)
Persistent hyperplastic primary vitreous (PHPV)
Optic nerve hypoplasia and other developmental retinal anomalies

📌 OMIM’ Evidence:
ATOH7 is listed as OMIM’609875 and is directly linked to Persistent hyperplastic primary vitreous, autosomal recessive, which includes retinal nonattachment as a core clinical feature.

One-Sentence:
ATOH7 on chromosome 10q21.3 is a key developmental transcription factor. Mutations affecting its coding sequence or its regulatory elements’ can disrupt retinal ganglion cell formation and lead to nonsyndromic congenital retinal nonattachment (NCRNA).

Summary:
There is evidence that nonsyndromic congenital retinal nonattachment is caused by mutation in the atonal homolog-7 (ATOH7) gene encoded on genomic coordinate 10:68,230,595  and cytoband 10q21.3 in humans.