erictopol.substack.com/p/the-missing-chip
2 corrections found
there are currently 2 academic centers that have established dedicated CHIP Clinics, both the University of Chicago and Cleveland Clinic
There are more than two academic CHIP clinics. By March 2026, other academic centers such as NYU Langone, UCSF, and Dana-Farber also publicly described dedicated CHIP programs or clinics.
Full reasoning
This count is too low. In addition to UChicago and Cleveland Clinic, other academic medical centers had already publicly described CHIP-specific clinics/programs before this March 15, 2026 post.
Examples:
- NYU Langone Health has a page titled "Clonal Hematopoiesis of Indeterminant Potential (CHIP) Clinic" describing a clinic within Perlmutter Cancer Center.
- UCSF Cardiology has a page for its "Clonal Hematopoiesis of Indeterminate Potential (CHIP) Center" and explicitly describes the "establishment of the CHIP-CVD clinic at UCSF."
- Dana-Farber Cancer Institute states that "Risk-predicting tests are now in use at Dana-Farber's specialized CHIP clinic."
Because multiple additional academic centers publicly identified CHIP clinics/centers, the statement that there were "currently 2" academic centers with dedicated CHIP clinics is factually incorrect.
3 sources
- Clonal Hematopoiesis of Indeterminant Potential (CHIP) Clinic | NYU Langone Health
The Clonal Hematopoiesis of Indeterminant Potential Clinic, part of NYU Langone's Perlmutter Cancer Center and its Center for Blood Cancers...
- Clonal Hematopoiesis of Indeterminate Potential (CHIP) Center | UCSF Cardiology
The establishment of the CHIP-CVD clinic at UCSF will provide tailored screening and cardiovascular care for patients with mutations in CHIP-related genes.
- What is Clonal Hematopoiesis of Indeterminate Potential (CHIP)? | Dana-Farber Cancer Institute
Risk-predicting tests are now in use at Dana-Farber's specialized CHIP clinic led by Lachelle Weeks, MD, PhD.
a clone size abnormality cutoff defined as 2% or greater of blood cells, or specifically a variant allele frequency (VAF) ≥ 2%
This mixes up allele fraction with cell fraction. CHIP is defined by a mutation with VAF ≥2%, which for a heterozygous mutation corresponds to about 4% of blood cells carrying the variant, not 2% of blood cells.
Full reasoning
The article equates "2% or greater of blood cells" with "variant allele frequency (VAF) ≥2%". Those are not the same thing.
A VAF of 2% means that 2% of the sequenced alleles carry the mutation. For a typical heterozygous somatic mutation, that corresponds to roughly 4% of circulating blood cells carrying the variant, not 2%.
A recent Haematologica review states that WHO defines CHIP as variants in blood cells at VAF ≥2%, and explicitly clarifies this as "≥4% of circulating blood cells carrying a heterozygous variant." The same review also explains that CHIP clones occupy at least 4% of the total proportion of blood cells when VAF is at least 2%.
So the post's wording understates the implied cell fraction by about half and conflates two different measurements: allele fraction and fraction of cells.
2 sources
- CHIP ahoy: charting a decade of discovery in clonal hematopoiesis | Haematologica
The World Health Organization (WHO) defines CHIP as CH with variants in myeloid malignancy-associated genes, present in blood cells at a VAF ≥2% (≥4% of circulating blood cells carrying a heterozygous variant)...
- CHIP ahoy: charting a decade of discovery in clonal hematopoiesis | Haematologica
Clonal hematopoiesis of indeterminate potential is defined when clones occupy at least 4% of the total proportion of blood cells (with variant allele fraction of at least 0.02 or 2%)...