Can twins be from different families?

Identical twins come from a single fertilized egg. Fraternal twins come from two different ones. They came from the same fertilized egg. Since embryo splitting is a random event that happens by chance, it doesn’t run in families.

Is depression genetic in twins?

Many individuals with depression can name other family members who also struggle with the same or similar illness. Early studies on the genetics of depression were conducted with twins. Identical twins share the same genes, while fraternal twins (and non-twin siblings) share only 50% of their genetic material.

What could cause variation in identical twins?

Research published on January 7 in the journal Nature Genetics shows that identical twins differ by an average of 5.2 genetic mutations. In such studies, scientists often assume that pairs of identical twins have identical DNA, so their differences can be explained by the environments they grew up in.

Do twins have more mental health issues?

The Journal of Psychiatric Practice has published new research on mental health in parents of multiples (twins, triplets, etc.). Parents of multiples reported higher rates of depression and anxiety than other parents. Despite a high rate of mental health concerns, few parents of multiples sought treatment.

Can 1 baby have 2 fathers?

It is possible for twins to have different fathers in a phenomenon called heteropaternal superfecundation, which occurs when two of a woman’s eggs are fertilized by sperm from two different men. Identical twins occur if that fertilized egg divides into two separate eggs, early in the pregnancy.

Can 1 baby have 2 biological fathers?

Unsourced material may be challenged and removed. Superfecundation is the fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse, which can lead to twin babies from two separate biological fathers.

What is the heritability rate of depression?

Major depressive disorder (MDD) is a common, complex trait with an estimated genetic heritability of ~40%.

Who carries the twin gene?

While men can carry the gene and pass it on to their daughters, a family history of twins doesn’t make them any more likely to have twins themselves. 3 But, if a father passes on the “twin gene” to his daughter, then she may have a higher chance than normal of having fraternal twins.

Is suicide common in twins?

However, twins had a substantially lower suicide rate compared with the general population, with 211 observed suicides versus 292.8 expected, corresponding to a standardised suicide rate of 0.74 for men (95% confidence interval 0.62 to 0.88) and 0.69 for women (0.55 to 0.86) (table).

Are twins more likely to have schizophrenia?

The researchers found that if one identical twin was affected by schizophrenia or schizophrenia spectrum disorders, the chance of the second being affected was about a third. For non-identical twins, the chance was far lower – only 7% for schizophrenia and 9% for schizophrenia spectrum disorders.

Is the risk of depression higher for parents of twins?

Parents Of Twins Run Higher Risk Of Depression Than Other New Parents : Shots – Health News Expectant parents of twins and other multiples may be ready for the joy and extra physical demands of caring for more than one baby. But few know the risk of depression and anxiety runs higher, too. Health News From NPR.

How many Swedish twins have suffered from depression?

To date, the largest of these individual twin studies have included 3,372 (4), 2,662 (5), and 2,974 (6) complete pairs. In this report, examining results of lifetime major depression as assessed at personal interview in over 15,000 complete pairs of twins from the national Swedish Twin Registry, we seek to address three questions.

Who is more at risk for depression, twins or singletons?

But, for parents of twins or other multiples; there’s good evidence that the percentage who experience depression may be much higher. A 2009 study, published in the journal Pediatrics found that new moms of multiples were 43 percent more likely to have postpartum depression than were mothers of singletons.

Is there a twin registry for major depression?

We simulated the CIDI-SF assessment of major depression in our sample of 7,521 personally interviewed twins from the Virginia Twin Registry for whom we had a complete set of items for DSM-III-R adapted from the Structured Clinical Interview for DSM-III-R (14).