Table 3.

Summary of the 20 most frequently ordered genetic tests according to ordering physician medical specialty

Gene evaluated (clinical component)	Total	Internal medicine	Obstetrics and gynecology	Pediatrics	Family medicine*
CFTR† (cystic fibrosis)	5625 (36.7)	250 (6.3)	5262 (57.6)	102 (4.8)	11 (14.5)
F2 (prothrombin)	2102 (13.7)	1675 (42)	194 (2.1)	218 (10.3)	15 (19.7)
HEXA (Tay–Sachs disease)	1028 (6.7)	18 (0.5)	969 (10.6)	39 (1.8)	2 (2.6)
HFE (hereditary hemochromatosis)	672 (4.4)	616 (15.4)	5 (0.1)	31 (1.5)	20 (26.3)
BCR-ABL (chronic myelogenous leukemia)	629 (4.1)	606 (15.2)	1 (0)	22 (1)	–
ASPA (Canavan disease)	470 (3.1)	14 (0.4)	416 (4.6)	39 (1.8)	1 (1.3)
DYS (familial dysautonomia)	458 (3)	8 (0.2)	408 (4.5)	41 (1.9)	1 (1.3)
GBA (Gaucher disease)	365 (2.4)	23 (0.6)	281 (3.1)	61 (2.9)	–
FMR1 (fragile X syndrome)	279 (1.8)	21 (0.5)	172 (1.9)	86 (4.1)	–
SMPD1 (Niemann–Pick disease)	271 (1.8)	7 (0.2)	226 (2.5)	38 (1.8)	–
FRAXE (fragile X syndrome)	268 (1.8)	8 (0.2)	198 (2.2)	61 (2.9)	1 (1.3)
G6PD (glucose-6-phosphate dehydrogenase deficiency)	213 (1.4)	11 (0.3)	163 (1.8)	39 (1.8)	–
MCOLN1 (mucolipidoisis IV)	208 (1.4)	5 (0.1)	165 (1.8)	38 (1.8)	–
BLM (Bloom syndrome)	206 (1.3)	5 (0.1)	164 (1.8)	37 (1.8)	–
FANCC (Fanconia anemia)	202 (1.3)	6 (0.2)	158 (1.7)	38 (1.8)	–
MTHFR C677T (vascular risk)	130 (0.9)	20 (0.5)	102 (1.1)	8 (0.4)	–
MTHFR A1298C (vascular risk)	128 (0.8)	20 (0.5)	100 (1.1)	8 (0.4)	–
CFTR‡ (cystic fibrosis)	104 (0.7)	33 (0.8)	10 (0.1)	61 (2.9)	–
HBA1 (α thalassemia)	100 (0.7)	2 (0.1)	93 (1)	5 (0.2)	–
HTC2 (hypertrichosis)	98 (0.6)	1 (0)	1 (0)	96 (4.5)	–
<top 20	1764 (11.7)	643 (16.5)	44 (0.5)	1052 (49.6)	25 (33.0)

Values are number (%).

^*Empty cell indicates genetic test was not ordered.

^†Nominal genetic test classification (coded report).

^‡Narrative genetic test classification (text report).