i do not know about Islam but the the Dravidian Hindu allow marriage between cross-first cousin.
The Dravidian Hindus (mostly south India) find marriage between cross-first cousins (the related parents of each cousin being a brother and sister) to be a preferred marital union.
The Dravidian kinship system involves selective "cousinhood." One's father's brother's children and one's mother's sister's children are NOT cousins but brothers and sisters "one step removed." They are considered "consanguinous" and marriage with them is strictly forbidden as it is "incestuous." However, one's father's sister's children and one's mother's brother's children are considered cousins and potential mates . Marriages between such cousins are allowed and encouraged.
There is a clear distinction between cross cousin who are one's true cousins and parallel cousins who are in fact "siblings".
( http://en.wikipedia.org/wiki/Kinship_terminology )
In contrast, the Aryan Hindus (mostly north India) strongly oppose consanguineal marriages within seven generations on the male side, and five generations on the female side of the family.
Correct me if I'm wrong.
Anupamaa
