Table 2 Clinical data according to aetiological group.

Diagnosis	No (male)	Guthrie TSH (mU/l)	Age at scans (days)	Day of thyroxine*	TSH at scans (mU/l)
Athyreosis	11 (3)	258 (146–447)	16.5 (14–27)†	7 (4–15)	47.2 (2.8–204)
Ectopia	12 (3)	144 (41–465)	16 (13–49)	5.5 (0–15)	48 (5.8–35)
Hypoplasia	8 (0)	66 (23–255)	19 (15–243)	7 (0–12)	7.7 (1–71.9)
Dyshormono genesis	5 (2)	49 (16–300)	17 (17–83)	7 (0–8)	37 (5–68)

TSH, thyroid stimulating hormone.

Median (range) for each category is shown.

*The duration of thyroxine (interval between age at treatment and age at scanning) is shown in column 5.

†Except one infant who had scans at 15 months, having started treatment on day 11.