ichthyosis hystrix of Curth-Macklin

Summary

ichthyosis hystrix of Curth-Macklin (MONDO:0007808) is a disease caused by KRT1 (GenCC Definitive), with 1 cohort gene.

At a glance

• Prevalence: <1 / 1 000 000 (Worldwide) [Orphanet-validated]
• Causal gene: KRT1 (GenCC Definitive)
• Cohort genes: 1
• ClinVar variants: 5
• Phenotypes (HPO): 8

Clinical features

Epidemiology

Prevalence records

2 prevalence record(s), Orphanet:

Type	Class	Value	Geography	Validation
Cases/families		10	Worldwide	Validated
Point prevalence	<1 / 1 000 000		Worldwide	Validated

Signs & symptoms

Clinical features (HPO)

8 HPO clinical features (Orphanet curated; top 8 by frequency):

HPO ID	Term	Frequency
HP:0000962	Hyperkeratosis	Very frequent (80-99%)
HP:0001581	Recurrent skin infections	Very frequent (80-99%)
HP:0007447	Diffuse palmoplantar kyperkeratosis	Very frequent (80-99%)
HP:0008064	Ichthyosis	Very frequent (80-99%)
HP:0001371	Flexion contracture	Frequent (30-79%)
HP:0008404	Nail dystrophy	Frequent (30-79%)
HP:0007460	Autoamputation of digits	Occasional (5-29%)
HP:0011889	Bleeding with minor or no trauma	Occasional (5-29%)

Identifiers

Disease identifiers

Field	Value
Canonical name	ichthyosis hystrix of Curth-Macklin
Mondo ID	MONDO:0007808
MeSH	C536088
OMIM	146590
Orphanet	79503
SNOMED CT	254170001
UMLS	C1840296
MedGen	326700
GARD	0002954
NORD	1281
Is cancer (heuristic)	no

Also known as: Curth-Macklin type ichthyosis hystrix · ichthyosis histrix, curth-macklin type · Ichthyosis Hystrix, Curth Macklin Type · ichthyosis hystrix, Curth Macklin type · ichthyosis HYSTRIX, Curth-Macklin type · ichthyosis hystrix, Curth-Macklin type · IHCM

Data availability: 5 ClinVar variants · 3 GenCC gene-disease records.

Disease family

Classification path: disease › human disease › disease by body system or component › integumentary system disorder › skin disorder › epidermal disease › ichthyosis › inherited ichthyosis › keratinopathic ichthyosis › ichthyosis hystrix of Curth-Macklin

Related subtypes (4): epidermolytic ichthyosis, superficial epidermolytic ichthyosis, congenital reticular ichthyosiform erythroderma, epidermolytic nevus

Genetics & variants

GWAS landscape

No GWAS associations recorded — common-variant (GWAS) studies don’t cover this disease (typical for Mendelian / rare diseases). See the curated gene cohort and Mendelian overlap below.

Variant details and genetic-evidence tiers

ClinVar germline variants

5 retrieved; paginated sample, class counts are floors:

4 pathogenic, 1 pathogenic/likely pathogenic

ClinVar	Variant (HGVS)	Gene	Classification	Review
15919	NM_006121.4(KRT1):c.1609_1610delinsA (p.Gly537fs)	KRT1	Pathogenic	no assertion criteria provided
1799555	NM_006121.4(KRT1):c.1860dup (p.Gly621fs)	KRT1	Pathogenic	no assertion criteria provided
1799556	NM_006121.4(KRT1):c.1577del (p.Gly526fs)	KRT1	Pathogenic	no assertion criteria provided
432078	NM_006121.4(KRT1):c.1453C>T (p.Leu485Phe)	KRT1	Pathogenic/Likely pathogenic	criteria provided, multiple submitters, no conflicts
66636	NM_006121.4(KRT1):c.1556del (p.Gly519fs)	KRT1	Pathogenic	no assertion criteria provided

Genes & proteins

Mendelian disease overlap and somatic drivers

GenCC: 18 · Orphanet: 8 · OMIM-shared: 0 · Dual-evidence (GWAS+Mendelian): 0

GenCC gene–disease validity (cohort genes)

the Disease column is the GenCC-asserted condition — a cohort gene’s strongest validity may be for a related predisposition syndrome.

Gene	Classification	Inheritance	Disease	Records
KRT1	Definitive	Autosomal dominant	annular epidermolytic ichthyosis	18

Orphanet rare-disease linkage (cohort genes)

Gene	Orphanet ID	Rare disease
KRT1	Orphanet:2199	Epidermolytic palmoplantar keratoderma
KRT1	Orphanet:281139	Annular epidermolytic ichthyosis
KRT1	Orphanet:281190	Congenital reticular ichthyosiform erythroderma
KRT1	Orphanet:312	Autosomal dominant epidermolytic ichthyosis
KRT1	Orphanet:50942	Striate palmoplantar keratoderma
KRT1	Orphanet:530838	KRT1-related diffuse nonepidermolytic keratoderma
KRT1	Orphanet:538574	Palmoplantar keratoderma-hereditary motor and sensory neuropathy syndrome
KRT1	Orphanet:79503	Ichthyosis hystrix of Curth-Macklin

Cohort genes → proteins

1 cohort genes, 1 distinct canonical proteins.

Evidence partition

Subset	Genes
multi_evidence	1

Cohort genes (full)

Symbol	HGNC	Ensembl	UniProt	Name	Evidence
KRT1	HGNC:6412	ENSG00000167768	P04264	Keratin, type II cytoskeletal 1	gencc,clinvar

Cohort function summary

Lead sentence per gene, UniProt-curated.

Symbol	Protein name	Function (lead sentence)
KRT1	Keratin, type II cytoskeletal 1	May regulate the activity of kinases such as PKC and SRC via binding to integrin beta-1 (ITB1) and the receptor of activated protein C kinase 1 (RACK1).

Protein-family classification

Druggable: 0 · Difficult: 0 · Unknown: 1 · Druggable fraction: 0.0

Family distribution

Cohort families vs a genome-wide background (hypergeometric, BH-FDR; fold = observed/expected). Counts kept; sorted by enrichment, so the catch-all Other/Unknown bucket no longer leads.

Family	Genes	Fold	FDR
Other/Unknown	1	1.8×	0.558

Per-gene assignment

Symbol	Family	Druggable?	EC	InterPro (top 3)
KRT1	Other/Unknown	no		Keratin_II, IF_conserved, Keratin_2_head

Expression context

Cohort genes with no expression data: 0.

1 cohort gene are a single-cell marker in ≥1 SCXA experiment.

Breadth distribution (Bgee present_calls)

Bucket	Genes
narrow (1-5 tissues)	0
moderate (6-20)	0
broad (>20)	1
unknown	0

Top tissues across cohort

Tissue	Cohort genes
mammalian vulva	1
skin of hip	1
upper leg skin	1

Per-gene tissue summary (top 30)

Symbol	Bgee breadth	FANTOM5 breadth	SCXA	Top tissues
KRT1	177	tissue_specific	marker	mammalian vulva, upper leg skin, skin of hip

Protein interactions among cohort

Intra-cohort edges: 0.

Hub genes (top 10 by interactor count)

Symbol	Interactor count
KRT1	2,716

Structural data

PDB: 1 · AlphaFold-only: 0 · No structure: 0

Cohort genes with PDB structures (top 30)

Symbol	UniProt	PDB entries
KRT1	P04264	3

Function

Pathway analysis

Distinct Reactome pathways touched by cohort: 10. Enrichment computed across 1 evidence-associated genes (1 with Reactome annotation).

Pathways by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 1 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

Pathway	Cohort genes	Fold	FDR	Sample cohort genes
Regulation of FXIIa and plasma kallikrein activity	1	1142.0×	0.009	KRT1
Differentiation of Keratinocytes in Interfollicular Epidermis in Mammalian Skin	1	278.5×	0.014	KRT1
Developmental Cell Lineages	1	223.9×	0.014	KRT1
FXIIa activates plasma kallikrein-kinin system	1	173.0×	0.014	KRT1
Formation of the cornified envelope	1	87.8×	0.023	KRT1
Keratinization	1	55.7×	0.030	KRT1
Innate Immune System	1	25.5×	0.054	KRT1
Neutrophil degranulation	1	23.1×	0.054	KRT1
Developmental Biology	1	14.5×	0.077	KRT1
Immune System	1	13.0×	0.077	KRT1

GO biological processes by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 1 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

GO term	Cohort genes	Fold	FDR	Sample cohort genes
complement activation, lectin pathway	1	1685.2×	0.003	KRT1
protein heterotetramerization	1	1053.2×	0.003	KRT1
cornification	1	1053.2×	0.003	KRT1
fibrinolysis	1	842.6×	0.003	KRT1
establishment of skin barrier	1	455.5×	0.004	KRT1
regulation of angiogenesis	1	421.3×	0.004	KRT1
intermediate filament organization	1	240.7×	0.005	KRT1
keratinization	1	234.1×	0.005	KRT1
negative regulation of inflammatory response	1	137.0×	0.008	KRT1
response to oxidative stress	1	130.6×	0.008	KRT1

Therapeutics

Drug target analysis

Approved (phase 4): 0 · Phase ≥3: 0 · Phased (≥1): 0 · Undrugged: 1

Druggability breadth: 0 of 1 evidence-associated genes (0%) have a ChEMBL target (buckets above are over the deeply-mined display cohort).

Top cohort targets by molecule count

Symbol	Molecules	Max phase
KRT1	0	0

Bioactivity and enzyme data

Enzyme cohort genes (≥1 EC): 0.

Pharmacogenomics

Cohort genes with a PharmGKB record: 1; with CPIC/DPWG dosing guidelines: 0.

No cohort gene has a CPIC/DPWG genotype-guided dosing guideline (PharmGKB).

Chemical tractability of cohort targets

0 approved/phased compounds have measured bioactivity against a cohort gene (and aren’t yet in disease-level trials). This is a research / tractability signal, NOT a therapeutic recommendation — a bioactivity row often reflects off-target or screening binding (e.g. promiscuous kinase inhibitors against a cohort kinase), implying no disease mechanism.

Druggability pyramid

Cohort genes binned by druggability tier (high → low):

Tier	Definition	Genes	Symbols
A	Approved (phase 4 drug)	0
B	Phased (≥1) drug, not yet approved	0
C	Druggable family + PDB, no drug	0
D	Druggable family + AlphaFold only, no drug	0
E	Difficult family or no structure, no drug	1	KRT1

Undrugged target profiles

1 cohort genes are undrugged. Ranked by ‘starting-point quality’ (assay depth + drugged-partner adjacency).

Symbol	ChEMBL assays	Drugged partners (top 3)
KRT1	0	—

Clinical trials & evidence

Clinical trials

Clinical trials: 0.