MeAnd23W_FIANew Table

The MeAnd23W_FIANew table stores shared DNA segments from 23andMe’s “Family Inheritance: Advanced” (FIA) comparison. Each row represents one shared segment between two people on one chromosome. This is the 23andMe equivalent of a chromosome browser table — it records the chromosome, start and end positions, the length of the shared segment in centimorgans, and whether the segment is fully identical.

Two people per segment: Every segment is stored from both directions. The two people compared are identified by ShareID and ShareID1 (each is a 23andMe profile ID). The application inserts the segment once with ShareID = profile A and ShareID1 = profile B, then inserts it again with the two IDs swapped, so a query starting from either person finds the segment.

Column Reference

Column	Type	Description
Id	int (PK)	Auto-incrementing primary key
loginUsername	string	DNAGedcom username who gathered this data. Set automatically on insert.
Chromosome	string	Chromosome name the segment is on (e.g., “1”, “2”, …, “X”)
StartPoint	string	Start position of the shared segment (genetic position)
EndPoint	string	End position of the shared segment (genetic position)
GeneticDistance	string	Length of the shared segment in centimorgans (cM), from the 23andMe `seg_cm` value
SNPs	string	Number of SNPs in the shared segment
Full	bool	True if the segment is fully identical (a full IBD match, from 23andMe’s `is_full_ibd` flag); false for a half match
ShareID1	string	23andMe profile ID of one of the two people compared
ShareID	string	23andMe profile ID of the other person compared. Together `ShareID` and `ShareID1` identify the pair that shares this segment.
created_date	string	Date the record was created (yyyy-MM-dd)
sync	string	Sync status flag. Set to “0” on insert; rows with sync = “0” are pending upload to DNAGedcom.

Note: The data class also contains two commented-out fields, Person1 and Person2. They are not part of the live table — the two people are identified by ShareID and ShareID1 instead.

How It’s Populated

FIA segments are gathered when chromosome / segment comparison is enabled for a 23andMe gather. For each relative, the application requests the genetic-relationship (segment) data for the pair from 23andMe. The two profile IDs are taken from the request URL: the gathered profile (psid) and the relative being compared.

Parse segments — the response is JSON containing a list of chromosomes, each with a list of matching_segments. The parser walks every chromosome and every segment.
Build the row — for each segment it records the chromosome name, start, end, seg_cm (stored in GeneticDistance), and the is_full_ibd flag (stored in Full).
Store both directions — the row is inserted with ShareID = the gathered profile and ShareID1 = the relative, then inserted again with those two IDs swapped.
Deduplicate — before each insert the application checks for an existing row with the same ShareID, ShareID1, Chromosome, and StartPoint; if one exists, the segment is skipped rather than duplicated.

On insert, loginUsername is set to the gathering DNAGedcom account and sync is set to “0”. Non-premium 23andMe accounts that return no chromosome data are skipped silently.

Related Tables

MeAnd23W_Relatives — the relative list. Its psid (gathered profile) and ehid (relative profile) correspond to the two IDs stored here as ShareID / ShareID1.
MeAnd23W_ICW — In Common With pairs, identified by the same 23andMe profile IDs.
MeAnd23W_Triag — triangulation flags built from overlapping FIA segments.
MeAnd23W_Shares — the shared/relatives-in-common profiles used to drive FIA comparisons.