Table 2.

Family-based (TDT) and case-control study of the RET+9.7 functional polymorphism rs2435357 on human chromosome 10q11.2.

HSCR	+	+	−	−	−
DS	+	−	+	−	+/−
Number of probands	62	62	30*	30*	60
Transmission of allele T	37	61	16	10	26
Transmission of allele C	13	8	15	20	35
Transmission frequency (τ)	0.74±0.06	0.88±0.04	0.52±0.09	0.33±0.09	0.43±0.06
Proband genotype: TT	12	30	2	1	3
CT	27	16	14	11	25
CC	23	16	14	18	32
Frequency of T allele	0.41±0.04	0.61±0.04	0.30±0.06	0.22±0.05	0.26±0.04

The individuals analyzed include those from Table 1 and additional samples as described in Methods.

^*HSCR-free controls (columns 4 and 5: total sample size of 60 matches the HSCR cases with and without DS in columns 2 and 3, respectively) do not demonstrate statistically significant differences in either transmission frequency (P= 0.15), genotype frequencies (P= 0.55) or allele frequency (P= 0.30) at rs2435357; consequently, the data were combined (column 6) for subsequent analysis.