# NM_000610.4(CD44):c.464A>T (p.Tyr155Phe)

https://sugi.bio/variant/cd44-p-tyr155phe

## Summary

**CD44 p.Tyr155Phe (c.464A>T)** is classified **Uncertain significance** in CD44 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-08-19). AlphaMissense: likely benign (0.3075); Absent from gnomAD v4.1.

**At a glance:** Uncertain significance · review: Single submitter · 1 submitter · AlphaMissense likely benign · absent from gnomAD v4.1

## For patients & families {#patients}

This is a change in the CD44 gene that is currently of uncertain significance — a definitive interpretation has not yet been established, submitted by 1 submitter.

*Reference information, not medical advice, and not a prediction for any individual. A genetic counselor or clinician can interpret what it means for you and your family.*

**Support & next steps:** [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [CD44](https://sugi.bio/atlas/gene/CD44/) |
| Protein change (HGVS p.) | p.Tyr155Phe |
| Coding change (HGVS c.) | c.464A>T |
| MANE Select transcript | [NM_000610](https://www.ncbi.nlm.nih.gov/nuccore/NM_000610) |
| Variant type | single nucleotide variant |
| Location | chr11:35189862-35189862 (GRCh38) |
| ClinVar | [VCV4222932](https://www.ncbi.nlm.nih.gov/clinvar/variation/4222932/) |

**All HGVS expressions:** `LRG_815:g.55993A>T`, `LRG_815t1:c.464A>T`, `LRG_815t2:c.464A>T`, `NC_000011.10:g.35189862A>T`, `NC_000011.9:g.35211409A>T`, `NG_008937.1:g.55993A>T`, `NM_000610.4:c.464A>T`, `NM_001001389.2:c.464A>T`, `NM_001001390.2:c.464A>T`, `NM_001001391.2:c.464A>T`, `NM_001001392.2:c.233+13122A>T`, `NM_001202555.2:c.464A>T`, `NM_001202556.2:c.464A>T`, `NM_001202557.2:c.464A>T`, `NM_001440324.1:c.464A>T`, `NM_001440325.1:c.464A>T`, `NM_001440326.1:c.464A>T`, `NM_001440327.1:c.464A>T`, `NM_001440328.1:c.464A>T`, `NM_001440329.1:c.452A>T`, `NM_001440330.1:c.464A>T`, `NM_001440331.1:c.395A>T`, `NM_001440332.1:c.464A>T`, `NM_001440333.1:c.464A>T`, `NM_001440334.1:c.464A>T`, `NM_001440335.1:c.464A>T`, `NM_001440336.1:c.464A>T`, `NM_001440337.1:c.464A>T`, `NM_001440338.1:c.464A>T`, `NM_001440339.1:c.464A>T`, `NM_001440340.1:c.464A>T`, `NM_001440341.1:c.464A>T`, `NM_001440342.1:c.464A>T`, `NM_001440343.1:c.464A>T`, `NM_001440344.1:c.464A>T`, `NM_001440345.1:c.464A>T`, `NM_001440346.1:c.464A>T`, `NM_001440347.1:c.464A>T`, `NM_001440348.1:c.464A>T`, `NM_001440349.1:c.464A>T`, `NM_001440350.1:c.464A>T`, `NM_001440351.1:c.464A>T`, `NM_001440352.1:c.464A>T`, `NM_001440353.1:c.464A>T`, `NM_001440354.1:c.464A>T`

## Computational & population evidence {#evidence}

**Concordance:** ClinVar classifies this **uncertain**; the computational predictors unanimously lean **tolerated** — a triage signal, not a reclassification.

- AlphaMissense **likely benign** (0.3075)
- REVEL 0.253 (benign-leaning) — agrees with AlphaMissense
- SaProt LLR -6.194 (tolerated) — agrees with AlphaMissense
- → **In-silico consensus:** AlphaMissense, REVEL and SaProt all call this tolerated
- SpliceAI predicts **acceptor gain** (Δ 0.44) — a splice-altering prediction on an uncertain variant — a signal for review
- Conservation: phyloP 11.255, GERP 2.75, phastCons 1 — highly conserved (differs from AlphaMissense)
- CADD: **PHRED 25.4**. No single ClinGen-calibrated threshold exists and the expert panels that use CADD disagree — GUCY2D/AIPL1 require ≥ 20.0 for an untranslated-region variant, ABCA4 ≥ 28.1 for a synonymous or indel variant, the Pulmonary Hypertension panel imports Pejaver 2022's missense-calibrated numbers, and the Antibody Deficiencies panel declines CADD entirely for PIK3CD. CADD v1.7 also incorporates Zoonomia phyloP, so it partly re-expresses the conservation above. *Descriptive; no threshold applied.*
- Regional missense constraint: **o/e 0.78** across the covering region of the MANE Select transcript (35,139,304–35,196,830), spanning 57,526 bp. Chi-square p 7.9e-05. Describes the region, not this allele; gnomAD v4.1.1's own constrained determination. *Descriptive; no ACMG code applied.*
- SpliceAI deltas (raw): acceptor loss **0.02**, donor loss **0.00**, acceptor gain **0.44**, donor gain **0.00**. Largest is acceptor gain.
- SpliceAI deltas (masked): acceptor loss **0.00**, donor loss **0.00**, acceptor gain **0.44**, donor gain **0.00**.
- Population frequency: **absent from gnomAD v4.1** — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

*Computational predictors are not independent (ClinGen Variant Classification guidance): AlphaMissense (Cheng et al. 2023) carries the ACMG weight for missense and conservation (phyloP/GERP/phastCons) for non-missense; REVEL (Pejaver-2022 calibrated strength bands) and SaProt (Su et al. 2023, structure-aware, ClinVar-independent protein language model, raw LLR) are shown as orthogonal agreement signals, not additive. For frequency, the gnomAD v4.1 grpmax filtering allele frequency (FAF95) is ClinGen's designated BA1/BS1 input (gnomAD v4 guidance v3.0, June 2025); BA1/BS1 thresholds are disease-specific, not a blanket 5%. Predictions, not a clinical determination.*

## Gene constraint & dosage {#gene-context}

**CD44** population constraint: LOEUF 0.654, pLI 0.0016068, missense-Z 0.90454. *Lower LOEUF and higher pLI indicate a gene that tolerates loss-of-function poorly; ClinGen dosage is the curated haploinsufficiency call.*

## Protein context {#protein}

Residue **155** lies in a β-strand.

AlphaFold model confidence (whole protein): pLDDT 53.31, 21% of residues very-high.

**7 experimental structure(s)** (PDB): [1POZ](https://www.rcsb.org/structure/1POZ), [1UUH](https://www.rcsb.org/structure/1UUH), [2I83](https://www.rcsb.org/structure/2I83), [32NZ](https://www.rcsb.org/structure/32NZ), [4PZ3](https://www.rcsb.org/structure/4PZ3), [4PZ4](https://www.rcsb.org/structure/4PZ4).

## What this gene does {#gene-function}

*Describes the biological roles of CD44 (the gene this variant disrupts) — not effects measured for this specific variant. A damaging variant is expected to affect these functions and pathways; the degree depends on the variant.*

**How this variant is thought to act:** CD44's established molecular role includes hyaluronic acid binding.


### Pathways affected {#pathways}

CD44 participates in **10 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| [Cell surface interactions at the vascular wall](https://reactome.org/content/detail/R-HSA-202733) | curated |
| [Degradation of the extracellular matrix](https://reactome.org/content/detail/R-HSA-1474228) | curated |
| [Developmental Lineage of Mammary Gland Luminal Epithelial Cells](https://reactome.org/content/detail/R-HSA-9927418) | curated |
| [Developmental Lineage of Mammary Gland Myoepithelial Cells](https://reactome.org/content/detail/R-HSA-9927432) | curated |
| [Developmental Lineage of Mammary Stem Cells](https://reactome.org/content/detail/R-HSA-9938206) | curated |
| [Hyaluronan degradation](https://reactome.org/content/detail/R-HSA-2160916) | curated |
| [Hyaluronan metabolism](https://reactome.org/content/detail/R-HSA-2142845) | curated |
| [Integrin cell surface interactions](https://reactome.org/content/detail/R-HSA-216083) | curated |
| [Interferon gamma signaling](https://reactome.org/content/detail/R-HSA-877300) | curated |
| [Neutrophil degranulation](https://reactome.org/content/detail/R-HSA-6798695) | curated |

### Molecular function & processes (GO — experimentally supported) {#go}

**Molecular function:** hyaluronic acid binding, signaling receptor activity, cargo receptor activity.

**Biological process:** endocytosis, cell adhesion, cell migration, hyaluronan catabolic process, positive regulation of heterotypic cell-cell adhesion, T cell activation.

## Clinical significance {#significance}

**Uncertain significance** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2025-08-19.

**Submitter consensus:** unanimous (1/1 Uncertain significance).

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| Ambry Genetics | Uncertain significance | criteria provided, single submitter | clinical testing | 2025-08-19 |

**Reported phenotype names (ClinVar):** not specified, AllHighlyPenetrant.

## Similar variants {#similar}

Related CD44 variant pages (same residue, condition, or type): [CD44 c.367+7T>C](/variant/cd44-c-367-plus-7t-c), [CD44 p.Arg463Gln](/variant/cd44-p-arg463gln), [CD44 p.Arg673Gln](/variant/cd44-p-arg673gln), [CD44 p.Gly462=](/variant/cd44-p-gly462), [CD44 p.Ile457Val](/variant/cd44-p-ile457val), [CD44 p.Phe245=](/variant/cd44-p-phe245), [CD44 p.Thr163=](/variant/cd44-p-thr163), [CD44 p.Thr393Met](/variant/cd44-p-thr393met).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-11); gnomAD v4.1 (Broad Institute, built 2026-10-06); AlphaMissense (Cheng et al. 2023, © Google DeepMind — CC BY 4.0, built 2026-01-27); REVEL (Ioannidis et al. 2016 — ODbL, built 2026-07-13); SaProt (Su et al. 2023 — MIT, built 2026-07-14); SpliceAI (Illumina — free for non-commercial use, built 2026-10-13); CADD (Rentzsch et al. 2019, University of Washington — free for non-commercial use, built 2026-10-10); Conservation (phyloP/phastCons/GERP) (UCSC hg38 470-way mammal (Hiller Lab) + Ensembl Compara, built 2026-07-12); gnomAD Non-coding Constraint (Gnocchi) (Chen et al. 2024, Broad Institute — CC0, built 2026-10-11); gnomAD Regional Missense Constraint (Broad Institute — CC0, built 2026-10-13); Pangolin (Zeng & Li 2022 — CC BY 4.0, built 2026-10-11); Repeat regions (UCSC — RepeatMasker, TRF, segmental duplications, built 2026-10-11); ClinGen (ClinGen, built 2026-09-22); UniProt (CC BY 4.0); Reactome / GO (CC BY 4.0, built 2026-09-23); MaveDB (per-record license, built 2026-10-11); CIViC (CC0, built 2026-09-22); Orphanet (Orphanet, built 2026-06-12)

*Primary record: NCBI ClinVar (variation 4222932). Classifications reflect these databases as of the page's build date and may change. Free reference use — not medical advice; consult the primary submitters and a clinician.*