Page 75 of The Bone Code
She answered right away. Sounds of traffic and children shouting suggested she was outside. Panting suggested she might be running.
“I’m sorry to bother you on a weekend.”
“No worries. I’m jogging. I hate jogging.” Her words came out in short little bursts.
I got straight to it, didn’t mention Ryan. “Have you heard of forensic genetic genealogy?”
“Are you joking?”
“No.”
“Of course, I’ve heard of it. Those blokes are onfuego, claiming to be cracking a cold case a week.”
“Could it be done on the bones I exhumed?”
“The container woman and kid?”
“Yes.”
She didn’t hesitate. “Not a chance.”
“Why not?” Fighting to hide my disappointment.
“First off, our lab doesn’t do SNP testing. Only STR.”
“Short tandem repeat.”
“Yes.” I heard her pausing to take a breath. “The kind of profile that goes into a database like CODIS to search for possible matches. Forensic genetic genealogy uses SNP genotype data.”
“Single nucleotide polymorphism.”
Based on the meager knowledge I’d acquired from reading and from colleagues in molecular biology, I understood that an SNP involved a substitution of a single one of four possible bases, A, T, C, or G, at a particular location on the DNA molecule.
I ran my distilled definition by Willoughby.
“Basically, that’s it. In layman’s terms, at a specific position along the double helix, where most folks have one gene, a minority have another.” Despite the labored breathing, Willoughby’s footfalls sounded rapid and steady. “And such polymorphisms, as we call them, are responsible for individual variations, things like differences in susceptibility to diseases like sickle-cell anemia and cystic fibrosis.”
The footfalls slowed, stopped. I heard rattling, then gulping.
“Look, Tempe, I live for this shit. But no can do. Even if we performed SNP at our lab, which we don’t, the bone you recovered was too degraded. I used up most of the sample for the STR.”
“Who does SNP testing?”
“As far as I know, mostly private labs.”
“Thanks.”
“I did nothing.”
“You took my call on a Saturday.”
“Did I mention I hate jogging?”
“Run, Forrest, run.”
“What?”
“Never mind.”
