Pregnancy loss answers
The genes behind pregnancy loss, explained plainly.
Most miscarriage is caused by chromosome problems. When losses recur with normal chromosomes, a rare single-gene cause is sometimes involved — in genes like TUBB8, NLRP7, and PADI6 that act in the egg and earliest embryo. These are rare, and none of this replaces your doctor or genetic counselor.
Genes tied to loss
A few of the best-studied examples.
These are some of the most established pregnancy-loss genes — Reticular's panel screens 750+. Each acts in the egg or the earliest days of development, and variants are rare and usually recessive.
| Gene | What it helps do | Typical pattern when altered | Read more |
|---|---|---|---|
| TUBB8 | Builds the egg's meiotic spindle for division. | Oocyte maturation arrest, fertilization failure, early arrest. | Guide |
| NLRP7 | Regulates early development and genomic imprinting. | Recurrent molar pregnancy and recurrent loss. | Guide |
| PADI6 | Subcortical maternal complex; supports genome activation. | Early embryonic arrest at the cleavage stage. | Guide |
| NLRP5, TLE6, KHDC3L, OOEP | Other subcortical maternal complex proteins. | Early embryonic arrest; some linked to imprinting or molar pregnancy. | Guide |
Why a karyotype misses it
Whole chromosome vs. a single gene.
A karyotype counts and checks whole chromosomes. A reproductive gene panel reads the individual genes inside them — a different scale entirely.
A karyotype checks the whole chromosome
It can catch an extra or missing copy of chromosome 10, but not a change inside a single gene on it.
A gene panel reads a single gene on it
TUBB8 sits at 10p15.3, the tip of chromosome 10's short arm — a variant there is invisible to a karyotype but is exactly what a reproductive gene panel looks for.
TUBB8 is a well-studied example: variants disrupt the egg's meiotic spindle and can cause eggs or early embryos to arrest (Feng et al., NEJM 2016). It is one of 750+ genes Reticular's panel screens.
Key pregnancy-loss genetics answers
Beyond chromosomes
Some pregnancy loss causes go beyond chromosome count.
Chromosome problems are the most common cause of miscarriage, and PGT-A and a karyotype are built to find them. When losses recur with normal chromosomes, the explanation can involve rare single-gene variants that those tests are not designed to see.
The genes
TUBB8, NLRP7, and PADI6 act in the egg and earliest embryo.
These maternal-effect genes govern the window between a mature egg and a few-day-old embryo. Variants are rare, and a finding is not a diagnosis, but they can explain a repeated pattern of arrest or loss that a chromosome test cannot.
How it differs
A reproductive-gene panel is not a karyotype or carrier screening.
A karyotype reads chromosome structure; carrier screening asks what a future child could inherit. A reproductive-gene panel asks whether a pregnancy can develop at all — a mostly separate set of genes that the other tests do not cover.
FAQ
Questions patients ask.
Yes. The most common genetic cause is a chromosome problem in the pregnancy, which accounts for about half of early losses. Less commonly, rare single-gene variants in reproductive genes can affect whether an egg matures, an embryo develops, or a pregnancy continues. Most single pregnancy losses are not caused by these rare genes.
A euploid result means the chromosome count looked typical, but it does not read individual genes. An embryo can be chromosomally normal and still carry a single-gene variant that disrupts early development, which is why some losses and arrested embryos have a normal chromosome result.
Maternal-effect genes are a key group, including TUBB8 (the egg's meiotic spindle), NLRP7 (recurrent molar pregnancy), and subcortical maternal complex genes such as PADI6, NLRP5, TLE6, KHDC3L and OOEP (early embryonic arrest). These are rare causes and do not explain most pregnancy loss.
A maternal-effect gene is one where the mother's genotype, acting through the egg, controls how the early embryo develops — independent of the embryo's own chromosomes. The egg is pre-stocked with proteins and RNA that run the first days of development, so a faulty maternal-effect gene can cause failure before the embryo's own genome switches on.
Carrier screening asks whether a future child could inherit a known recessive condition like cystic fibrosis. Reproductive-gene screening asks a different question: is there a genetic reason a pregnancy might not develop at all? The two mostly look at different genes, so a normal carrier screen does not cover this layer.
No. Reticular provides a research-backed reproductive-gene screen and genetic counseling. A finding is not a diagnosis, does not explain every loss, and should be interpreted with a fertility clinician and genetic counselor alongside the standard evaluation.
Reticular screening
Weighing genetic screening after loss?
Compare plans and what each one includes, or talk it through with a genetic counselor first.
Next reading
Go deeper without starting over.
The Reticular Fertility & Pregnancy Loss Panel
What the parent-only screen covers, the research behind it, and what a result can and cannot mean.
OpenThe genetic workup beyond a karyotype
What the standard recurrent-loss evaluation checks, and the single-gene layer it can miss.
OpenGenetic data privacy
How Reticular handles genetic data, report access, account deletion, and consent.
Open