About KaryoDraw
KaryoDraw is a free, browser-based tool that draws any karyotype written in ISCN 2024 notation and explains every symbol in plain language. It is built for the genetics community: students, genetic counselors, residents and fellows, laboratory staff, and anyone learning or teaching cytogenetics.
What it does
Type a designation such as 47,XX,+21 or 46,XY,t(9;22)(q34;q11.2) and KaryoDraw draws a correctly Giemsa-banded karyogram, aligns any derivative chromosomes against their normal homologs, and decodes every part of the notation into a sentence. You can switch between a highlight view that colors only the chromosomes involved and a realistic view that bands all 46, adjust the resolution from roughly 400 to 850 bands, and hover any band to read its coordinate and the biology of its stain. Every view has a shareable link and can be exported as an image or a one-page printable summary.
Who it is for
The tool is aimed at people preparing for genetic counseling and medical genetics board exams, including the ABGC and ABMGG, and at anyone who teaches cytogenetics and wants a fast way to show a karyotype with the reasoning spelled out. If you are new to the notation, the guide on how to read a karyotype walks through it from the chromosome count to every rearrangement symbol.
How the drawings are made
The chromosome banding is drawn from the UCSC cytoBandIdeo track for the human genome, build hg38. KaryoDraw parses the ISCN designation, rebuilds each derivative chromosome from its breakpoints, and places it next to a normal copy so the change is visible. The band coordinates it reports follow the standard region, band, and sub-band numbering counted outward from the centromere.
Privacy
KaryoDraw runs entirely in your browser, with no account and nothing to install. To keep improving the tool and to show the most-studied karyotypes, we record which karyotypes are drawn and which features are used. There are no cookies, no IP addresses stored, and no accounts. If something looks wrong, the Doesn't look right? button on any drawing flags it for review.
Not a diagnostic tool
KaryoDraw is an educational visualizer of cytogenetic nomenclature for learning and teaching. It is not a diagnostic tool and does not replace a clinical cytogenetics laboratory report. Clinical decisions should always rest on a validated laboratory result interpreted by a qualified professional.
Who makes it
KaryoDraw is developed and maintained by StudyRare, and it is open source. You can read the code, report an issue, or suggest an improvement on GitHub. Feedback of any kind is welcome and read.