I understand your concern and good to have contacted HCM for clarification.In humans, a single transverse palmar crease is a single crease that extends across the palm of the hand, formed by the fusion of the two palmar creases (known in the palmistry as the heart line and the head line ) is found in half of people with Down Syndrome.It is also found in 10% of the general population. Because it resembles the usual condition of non-human simians, it is also known as a simian crease or simian line.This is seen in the so-called trisomy syndromes , which represent a group of genetic disorders featured with an extra chromosome that creates trisomy in one of the 23 chromosome pairs. The two most common trisomy syndromes are - Down syndrome (trisomy 21), where the prevalence of the simian line is usually reported to be around 40%; - Edwards syndrome (trisomy 18), where the prevalence has been confirmed to be around 70% - which is higher than in any known human (sub-)population around the world. Down s syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21.It is typically associated with physical growth delays, characteristic facial features, and mild to moderate intellectual disability.The average IQ of a young adult with Down syndrome is 50, equivalent to the mental age of an 8- or 9-year-old child, but this varies widely. This is the reason for clumsy ,uncoordinated behaviour of your child . But the IQ of 106 is average by Wechsler classification. In effect, she will be an average child in scholastic performance and you can try giving her mental activity boosting games like chess and train her to behave more intelligently. Moreover as she grows up the level may be boosted up. I hope this explains your worries and I am free to answer more doubts if any. Regards