Hi Rose, The bone age scan is a simple x-ray of the hand/wrist than reveals how the ends of the bones are forming. This info can indicate if there is normal maturing of the bones. An untreated CAH child will show advanced aging of the bones. For example, when my daughter was 2, her bone age was that of a 4 ½ year old. My daughter was also very tall for her age and underweight before being diagnosed. Found a sight to look into for bone age scan. www.sleeptight.com/EncyMaster/B/bone_age.html You may also want to check out. www.sleeptight.com/EncyMaster/A/adrenogenital_syndrome.html (some of the other sites are better than this last one but it gives a quick overview) You did not mention if an ultrasound was ever done. This may be helpful to show the presence(small as they may be) of uterus and ovaries. Peg