Predispositions
Here we are not talking about carrier status but about genotypes that affect the person. There are three ways of getting there, and they are worth telling apart.
Both copies with the same variant
Both inherited with the same change, one from each parent.
Both copies affected, with different variants
It counts the same as homozygous: neither copy works properly.
A single copy is enough for it to be expressed
Here a single copy is enough. Being a healthy carrier is not possible.
If you were looking for the carrier section —a single copy, with no effect on your health, relevant for your children— it is in Carriers.
All 6 conditions, by what they mean for you
What was found
Factor V Leiden thrombophilia
A single copy is enough for it to be expressed — It requires no treatment and no monitoring in the absence of symptoms. It is worth having it on record in your medical history, though: it changes management in the setting of a scheduled surgery, a pregnancy, or the choice of a contraceptive. Mention it before starting hormonal contraception.
A single copy already increases the tendency to form clots: it multiplies the risk of venous thrombosis by 4 to 8. Even so, most people with this variant never have an episode. The risk becomes relevant when it combines with something else: surgery, prolonged immobilization, pregnancy, long trips, or estrogen-containing contraceptives.
See the 5 conditions analyzed with no findings
| Condition | Gene | Inheritance | Chip coverage | Source |
|---|---|---|---|---|
| Familial hypercholesterolemia | LDLR / APOB / PCSK9 | Alta | The chip covers this disease well | GeneReviews · familial hypercholesterolemia |
| Hereditary hemochromatosis | HFE | Baja a moderada, mayor en varones | The chip covers this disease well | GeneReviews · HFE hemochromatosis |
| Gilbert syndrome | UGT1A1 | Requires both copies | The chip covers this disease well | PharmGKB · UGT1A1 |
| Alpha-1 antitrypsin deficiency | SERPINA1 | High in PI*ZZ, especially with smoking | The chip covers this disease well | GeneReviews · alpha-1 antitrypsin |
| Malignant hyperthermia | RYR1 / CACNA1S | It only manifests under general anesthesia | Not assessable with this technology | GeneReviews · Malignant Hyperthermia |
See the 4 conditions this study could NOT evaluate
These conditions entered the panel and were left unanswered: they are not a “no findings”. They are listed one by one with the reason, because a negative that was never measured is not a negative. If any matters because of family history, another technique is required.
| Condition | Gene | Inheritance | Why it could not be done |
|---|---|---|---|
| Coffin-Siris syndrome | ARID2 | Dominant | the test did not measure any variant of this gene in this sample |
| oligodontia-cancer predisposition syndrome | AXIN2 | Dominant | the test did not measure any variant of this gene in this sample |
| Alport syndrome | COL4A4 | Semidominant | the test did not measure any variant of this gene in this sample |
| Gastrointestinal stromal tumor | PDGFRA | Dominant | the test did not measure any variant of this gene in this sample |
Measured against ClinVar and the chip's actual manifest: of the 252,170 pathogenic or likely pathogenic variants described, the array measures 24,663 — 9.8%. But that average is misleading, because coverage rises a great deal among the better-reviewed variants: it reaches 55% among three-star ones (5,990 of 10,801), against barely 3% among one-star ones. At the highest review level it reaches 95%, though there it is worth looking at the denominator before getting excited: it is 21 variants out of 22 in total. There are 1,087 conditions with at least three known variants and more than half of them measured, across 88 genes. The practical consequence is a single one and it is worth being clear about it: this study can FIND a known pathogenic variant, but it cannot RULE ONE OUT. A negative result here is not equivalent to that of a sequencing test.
A genotyping array detects common, known variants well, but most genetic diseases of this kind are due to rare variants, or ones private to each family. That is why a negative result here reduces the probability but does NOT rule anything out. If there is clinical suspicion or a family history, which test comes next is decided by the professional who sees you: the clinical picture outranks this report.
1 condition could not be evaluated with this platform. They appear anyway, with the reason, because a report that leaves out what it did not measure reads as if it had ruled it out.