Nonsyndromic congenital nail disorder 8: genes and variants
Nonsyndromic congenital nail disorder 8 is linked to 1 analyzed protein (COL7A1). 15 DNA variants are known to cause it; 25 more are uncertain, and 0 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Also known as: nonsyndromic congenital nail disorder 4
Genes linked to Nonsyndromic congenital nail disorder 8
COL7A1: Collagen alpha-1(VII) chain
It forms anchoring fibrils that secure the epidermal basement membrane to the underlying dermis. Pathogenic variants cause dystrophic epidermolysis bullosa, with skin fragility and scarring ranging from localized disease to severe generalized forms with major complications.
15 disease-causing and 25 uncertain variants in COL7A1 are linked to Nonsyndromic congenital nail disorder 8.
Where Nonsyndromic congenital nail disorder 8 variants cluster
- COL7A1 Triple-helical region (positions 1254–2784): 15 of 15 disease-causing changes, 1.9× more than its size predicts.
Known disease-causing variants in Nonsyndromic congenital nail disorder 8
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| COL7A1 G2009E | 2009 | Cell attachment site | Disease-causing (★★) |
| COL7A1 G1284S | 1284 | Interrupted collagenous region | Disease-causing (★★) |
| COL7A1 G1569R | 1569 | Triple-helical region | Disease-causing (★★) |
| COL7A1 G1703E | 1703 | Triple-helical region | Disease-causing (★★) |
| COL7A1 G2366A | 2366 | Triple-helical region | Disease-causing (★★) |
| COL7A1 G2575W | 2575 | Triple-helical region | Disease-causing (★★) |
| COL7A1 G2647S | 2647 | Triple-helical region | Disease-causing (★★) |
| COL7A1 G1854R | 1854 | Triple-helical region | Disease-causing (★★) |
| COL7A1 G2132D | 2132 | Triple-helical region | Disease-causing (★★) |
| COL7A1 R2745Q | 2745 | Triple-helical region | Disease-causing (★★) |
| COL7A1 G1299V | 1299 | Interrupted collagenous region | Disease-causing (★) |
| COL7A1 G1329E | 1329 | Interrupted collagenous region | Disease-causing (★) |
| COL7A1 G2218A | 2218 | Triple-helical region | Disease-causing (★) |
| COL7A1 G2333R | 2333 | Triple-helical region | Disease-causing (★) |
| COL7A1 G2683C | 2683 | Triple-helical region | Disease-causing (★) |
Which prediction tools work for Nonsyndromic congenital nail disorder 8
How often each tool ranks a disease-causing variant above a harmless one (AUROC × 100).
- phyloP: 96 out of 100
- PolyPhen-2: 95 out of 100 (learned from overlapping clinical labels, so this is optimistic)
- CADD: 88 out of 100
- SIFT: 85 out of 100
Same protein, different disease
- Epidermolysis bullosa dystrophica is also caused by COL7A1 variants; they fall mostly in different places as the Nonsyndromic congenital nail disorder 8 variants (64 disease-causing).
- Recessive dystrophic epidermolysis bullosa is also caused by COL7A1 variants; they fall mostly in different places as the Nonsyndromic congenital nail disorder 8 variants (53 disease-causing).
- Generalized dominant dystrophic epidermolysis bullosa is also caused by COL7A1 variants; they fall mostly in different places as the Nonsyndromic congenital nail disorder 8 variants (26 disease-causing).
- Dominant dystrophic epidermolysis bullosa with absence of skin is also caused by COL7A1 variants; they fall mostly in different places as the Nonsyndromic congenital nail disorder 8 variants (12 disease-causing).
- Transient bullous dermolysis of the newborn is also caused by COL7A1 variants; they fall mostly in different places as the Nonsyndromic congenital nail disorder 8 variants (10 disease-causing).
Diseases related to Nonsyndromic congenital nail disorder 8
- Epidermolysis bullosa dystrophica, also linked to COL7A1
- Recessive dystrophic epidermolysis bullosa, also linked to COL7A1
- Generalized dominant dystrophic epidermolysis bullosa, also linked to COL7A1
- Dominant dystrophic epidermolysis bullosa with absence of skin, also linked to COL7A1
- Transient bullous dermolysis of the newborn, also linked to COL7A1
- Epidermolysis bullosa simplex 1A, generalized severe, also linked to COL7A1
- Pretibial dystrophic epidermolysis bullosa, also linked to COL7A1
- Epidermolysis bullosa pruriginosa, also linked to COL7A1
- Epidermolysis bullosa, also linked to COL7A1
Frequently asked questions
Which genes are linked to Nonsyndromic congenital nail disorder 8?
In CATVariant, Nonsyndromic congenital nail disorder 8 is linked to 1 analyzed protein: COL7A1 (Collagen alpha-1(VII) chain).
How many genetic variants are linked to Nonsyndromic congenital nail disorder 8?
53 variants: 15 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 25 are of uncertain significance or have conflicting reports.
Which uncertain variants in Nonsyndromic congenital nail disorder 8 look disease-causing?
None of the uncertain variants currently reaches the likely-pathogenic range on computable evidence alone.
Which variant effect predictor works best for Nonsyndromic congenital nail disorder 8?
Among tools not trained on clinical labels, phyloP separates this disease's known disease-causing variants from harmless ones best (AUROC 0.96, based on 12 disease-causing and 198 harmless variants).
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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