Table 2. Orphan FEB and GEFS+ loci.

Phenotype	OMIM ID	Locus	Coordinates	Candidates			Ref.
				total	HBA	GEO
FEB1	%121210	8q13-q21	chr8:66,932,638–72,988,347	31	19	28	[29]
FEB2	%602477	19p13.3	chr19:3,075,844–7,583,551	112	76	105	[14]
FEB4†	#604352	5q14-q15	chr5:89,166,516–110,036,710	50	39	49	[40]
FEB4	#604352	5q14.3-q23.1	chr5:88,728,695–122,125,234	93	70	88	[28]
(Deprez et al.) ‡
FEB5	%609255	6q22-q24	chr6:129,947,710–133,546,636	29	12	27	[15]
FEB6	%609253	18p11.2	chr18:10,133,108–12,597,248	12	11	12	[52]
FEB7	%611515	21q22	chr21:32,533,246–39,359,893	59	43	54	[58]
FEB9	%611634	3p24.2-p23	chr3:24,924,673–33,687,557	32	26	29	[53]
FEB10	%612637	3q26.2-q26.33	chr3:170,902,825–181,419,957	28	24	28	[63]
GEFS+4	%609800	2p24	chr2:17,491,922–20,329,508	13	8	11	[67]
GEFS+6	%612279	8p23-p21	chr8:6,940,747–15,649,945	56	20	36	[72]
GEFS+6	%612279	8p23.1-p21.3	chr8:6,940,747–20,367,401	79	35	59	[72]
(family 15173)*
GEFS+N	–	6q16.3-q22.31	chr6:101,352,134–119,553,944	89	60	85	[73]

Mapped FEB and GEFS+ loci for which the susceptibility or disease-causing gene has not yet been identified. Coordinates correspond to the regions flanked by genetic markers identified in the respective studies. The number of candidate genes in the mapped regions is indicated as a total number and the subset of genes for which HBA and GEO expression profiles are available, respectively (see Table S4 for the complete lists of candidates). Note: “GEFS+N” is not an official symbol (N = novel).

^†The implication of MASS1 in FEB4 [25] is controverse; Deprez et al [28] describe a case with an overlapping linkage interval (^‡) without evidence for MASS1 mutations (see text).

*Baulac et al [72] describe also a family with a larger linkage interval; since it is not clear whether the genetic cause is the same, we consider this interval as a distinct orphan locus.