# NM_001909.5(CTSD):c.697C>T (p.Leu233=)

https://sugi.bio/variant/ctsd-p-leu233

## Summary

**CTSD p.Leu233= (c.697C>T)** is classified **Conflicting classifications of pathogenicity** in CTSD (ClinVar, Conflicting submitters, 2 submitters; last evaluated 2026-01-26). Ultra-rare (popmax 0.0866%, afr); Associated with neuronal ceroid lipofuscinosis.

**At a glance:** Conflicting classifications of pathogenicity · review: Conflicting submitters · rsID rs142330967 · 2 submitters · 1 linked condition · ultra-rare (popmax 0.0866%, afr)

## For patients & families {#patients}

This is a change in the CTSD gene that is of uncertain or conflicting significance (submitters disagree on it), submitted by 2 submitters, and is linked to neuronal ceroid lipofuscinosis.

*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.*

|  |  |
| --- | --- |
| Clinical trials | 7 registered for this condition — see ClinicalTrials.gov |

**Support & next steps:** [Condition overview & support (NIH GARD)](https://rarediseases.info.nih.gov/diseases/0010739/index) · [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [CTSD](https://sugi.bio/atlas/gene/CTSD/) |
| Protein change (HGVS p.) | p.Leu233= |
| Coding change (HGVS c.) | c.697C>T |
| MANE Select transcript | [NM_001909](https://www.ncbi.nlm.nih.gov/nuccore/NM_001909) |
| dbSNP | [rs142330967](https://www.ncbi.nlm.nih.gov/snp/rs142330967/) |
| Variant type | single nucleotide variant |
| Location | chr11:1757331-1757331 (GRCh38) |
| ClinVar | [VCV700124](https://www.ncbi.nlm.nih.gov/clinvar/variation/700124/) |

**All HGVS expressions:** `NC_000011.10:g.1757331G>A`, `NC_000011.9:g.1778561G>A`, `NG_008655.1:g.11662C>T`, `NM_001909.5:c.697C>T`

## Computational & population evidence {#evidence}

**Concordance:** Mixed / partial computational evidence (see below).

- **Missense predictors (AlphaMissense/REVEL/SaProt) do not apply** to this variant type — they score amino-acid substitutions only. For non-missense variants the computational signal comes from conservation (below), not from a missing predictor score.
- Conservation: phyloP 4.31, GERP -2.1, phastCons 1 — highly conserved position (PP3-type support)
- CADD: **PHRED 9.666**. 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.*
- SpliceAI: **below the reporting threshold**. This position is scored for a different substitution (G>C, Δ0.62 donor gain), so this allele was evaluated and its deltas all fell under Δ0.2 — a prediction of no splicing effect for this allele, not a gap in our data. *No ACMG code assigned.*
- Population frequency (gnomAD v4.1): grpmax **0.0866%** (afr) · FAF95 0.0697% · FAF99 0.0635% · 65/75,060 in the highest group · 75/1,613,426 alleles overall — ultra-rare (popmax 0.0866%, afr).

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| African / African-American (grpmax) | 0.0866% | 1,155 |
| Remaining individuals (not grpmax-eligible) | 0.0112% | 8,927 |
| South Asian | 0.0011% | 91,044 |
| European (non-Finnish) | 0.00017% | 589,824 |

*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}

**CTSD** population constraint: LOEUF 0.886, pLI 1.4812e-06, missense-Z 1.2419. *Lower LOEUF and higher pLI indicate a gene that tolerates loss-of-function poorly; ClinGen dosage is the curated haploinsufficiency call.*

Curated gene–disease validity (ClinGen):

- **neuronal ceroid lipofuscinosis** — Definitive (AR)

## Protein context {#protein}

Residue **233** lies in a β-strand; the peptidase a1 domain.

AlphaFold model confidence (whole protein): pLDDT 85.69, 63% of residues very-high.

**9 experimental structure(s)** (PDB): [1LYA](https://www.rcsb.org/structure/1LYA), [1LYB](https://www.rcsb.org/structure/1LYB), [1LYW](https://www.rcsb.org/structure/1LYW), [4OBZ](https://www.rcsb.org/structure/4OBZ), [4OC6](https://www.rcsb.org/structure/4OC6), [4OD9](https://www.rcsb.org/structure/4OD9).

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

*Describes the biological roles of CTSD (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:** CTSD's established molecular role includes peptidase activity. p.Leu233= falls in the peptidase a1 domain.


### Pathways affected {#pathways}

CTSD participates in **7 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| [Collagen degradation](https://reactome.org/content/detail/R-HSA-1442490) | curated |
| [Estrogen-dependent gene expression](https://reactome.org/content/detail/R-HSA-9018519) | curated |
| [Insulin receptor recycling](https://reactome.org/content/detail/R-HSA-77387) | curated |
| [MHC class II antigen presentation](https://reactome.org/content/detail/R-HSA-2132295) | curated |
| [Metabolism of Angiotensinogen to Angiotensins](https://reactome.org/content/detail/R-HSA-2022377) | curated |
| [Neutrophil degranulation](https://reactome.org/content/detail/R-HSA-6798695) | curated |
| [Processing of antigen in germinal center B cells](https://reactome.org/content/detail/R-HSA-9979719) | curated |

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

**Molecular function:** peptidase activity.

**Biological process:** proteolysis, lipoprotein catabolic process, positive regulation of apoptotic process, regulation of establishment of protein localization, execution phase of apoptosis.

## Clinical significance {#significance}

**Conflicting classifications of pathogenicity** — review status Conflicting submitters *(criteria provided, conflicting classifications)*, last evaluated 2026-01-26.

**Submitter consensus:** conflicting (1 Uncertain significance, 1 Likely benign).

**Submission history:** 2 submissions (2025–2026); classifications have differed over time.

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| GeneDx | Uncertain significance | criteria provided, single submitter | clinical testing | 2025-04-30 |
| Labcorp Genetics (formerly Invitae), Labcorp | Likely benign | criteria provided, single submitter | clinical testing | 2026-01-26 |

## Associated conditions {#conditions}

[neuronal ceroid lipofuscinosis](https://sugi.bio/atlas/disease/neuronal-ceroid-lipofuscinosis/).

**Reported phenotype names (ClinVar):** Neuronal ceroid lipofuscinosis, not provided, Neuronal Ceroid Lipofuscinoses, none provided.

## Similar variants {#similar}

Related CTSD variant pages (same residue, condition, or type): [CTSD c.228+1G>A](/variant/ctsd-c-228-plus-1g-a), [CTSD p.Glu82Ter](/variant/ctsd-p-glu82ter), [CTSD c.828-3C>A](/variant/ctsd-c-828-minus-3c-a), [CTSD p.Ala10Ser](/variant/ctsd-p-ala10ser), [CTSD p.Ala18Pro](/variant/ctsd-p-ala18pro), [CTSD p.Ala18Thr](/variant/ctsd-p-ala18thr), [CTSD p.Ala239Val](/variant/ctsd-p-ala239val), [CTSD p.Arg176Lys](/variant/ctsd-p-arg176lys).

### 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 700124). 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.*