Is a single transverse palmarcrease in both hands correlated to autism or disorders in the spectrum?

Single palmar crease: Single palmar creases are believed to develop around 12 weeks gestation. Any insult to the developing fetus can produce these creases and associated neurologic defects. Single palmar creases are most commonly associated with Down's Syndrome, but can also be associated with a number of other genetic defects, neurologic disorders and possibly Fetal Alcohol Syndrome.

Palmar crease: Children with a transverse palmar crease have been described in children with Downs syndrome Other children may have a crease but it does not mean that they have autism or autism spectrum

Not necessarily: There are people who have single palmar creases who are absolutely normal individuals.