Dr Drayna has already been involved in a twin study which revealed that the perception of musical pitch is highly heritable.

ECONOMIST: Twin research

The wing and part of the fuselage of the plane were being moved to Oceana for further study, but the remains of the jet's twin engines will remain at the crash site for now as investigators study them, the U.S. Atlantic fleet's aviation arm reported.

CNN: 'Oh my God!' Callers recount Navy jet crash

However, the study, at the hospital's twin research unit, found that identical twins were more likely to have a similar number of moles than twins who are not identical.

BBC: Twins offer skin cancer clue

Among fraternal twins, the likelihood that a second twin will have autism is 35% nearly twice the risk other siblings face, the study found.

WSJ: Why Kids Get Autism: New Genetic Clues

The largest-ever study of twins with ASD 192 pairs reported last year that when one identical twin has autism, there is only a 70% chance that the other twin will, despite their identical genetic makeup.

WSJ: Why Kids Get Autism: New Genetic Clues