Table 1.

Frequencies of Sc and Xmrk in surveyed populations.

Population	Sex	N	Sc %	Xmrk %	Penetrance of Sc %
Tanute	Male	51	33.3 (17)	60.8 (31)	54.8
	Female	41	2.4 (1)	14.6 (6)	16.7
	Total	92	17.2 (16)	40.2 (37)	43.2
Conchita	Male	44	43.2 (19)	81.8 (36)	52.8
	Female	28	32.1 (9)	57.1 (16)	56.3
	Total	72	38.9 (28)	72.2 (52)	53.8
Chalpu.	Male	45	33.3 (15)	37.8 (17)	88.2
	Female	45	26.7 (12)	35.6 (16)	75.0
	Total	90	29.7 (27)	36.7 (33)	81.8
San Martín	Male	62	1.6 (1)	4.8 (3)	33.3
	Female	53	1.9 (1)	3.8 (2)	50.0
	Total	115	1.7 (2)	4.3 (5)	40.0

Parentheses indicate the actual number of individuals. The penetrance of Sc phenotype was calculated as the number of Sc individuals divided by the number of Xmrk individuals in that particular row.