08/19/2026
What do all those letters and symbols in a genetics report actually mean?
Today, we're continuing the talk from genetic counselor Emily Bonkowski (ScM, CGC, St. Jude Children's Research Hospital), from our 2025 Family & Scientific Conference.
This time, we're exploring how to read the genetic code in a genetics report (found in the Variant column).
🧬 C-Dot and P-Dot
In the Variant column, you'll see something written out starting with a C. This is called c-dot notation, and it tells you where in the DNA sequence a change happened.
Then you also see something starting with a P. This is called p-dot notation, which indicates what the genetic change means for the protein being built from this DNA sequence.
🧬 Common Notations
You will also see different abbreviations and symbols in this column, including:
🔎 * (asterisk) = The gene stops prematurely
🔎 fs* = Frame shift
🔎 del = Deletion
🔎 ins = Insertion
🔎 delins = Deletion with insertion
🔎 dup = Duplication
🔎 +1 or -1 = Splice site
🔎 15q26.1 = Example of a deletion including multiple genes on chromosome 15
🧬 Types of Changes
Now, let's talk through some examples using the analogy of this sentence: the cat ate the fat rat. All of the words in this sentence are three letters long, which is how DNA is read — three letters at a time.
✏️ Truncation/Premature Stop: The cat ate (sentence doesn't finish)
✏️ Frameshift: The tat eth efa tra t (letters jumbled and shifted forward or down)
✏️ Missense: The hat ate the fat rat; The kat ate the fat rat (a single letter is changed out; sometimes the meaning changes and sometimes it doesn't)
Next week, we will wrap up the final topics discussed in Emily's session.
You can watch Emily's full talk here: https://www.youtube.com/watch?v=EU9ov_gfrNY
