| Abnormal brain choline/creatine ratio by MRS | HP:0012709 | | |
| Abnormal brain FDG positron emission tomography | HP:0012658 | | |
| Abnormal brain positron emission tomography | HP:0012657 | | |
| Abnormal brainstem auditory-evoked potentials | HP:0006958 | | |
| Abnormal brainstem MRI signal intensity | HP:0012747 | | |
| Abnormal branching pattern of the aortic arch | HP:0011587 | | |
| Abnormal calcification of the carpal bones | HP:0009164 | | |
| Abnormal carpal bones | HP:0001191 | | |
| Abnormal cartilage collagen | HP:0008271 | | |
| Abnormal cartilage matrix | HP:0008178 | | |
| Abnormal cartilage morphology | HP:0002763 | | |
| Abnormal CD4-positive, CD25-positive, alpha-beta regulatory T cell count | HP:0030335 | | |
| Abnormal CD4-positive, CD25-positive, alpha-beta regulatory T cell morphology | HP:0030334 | | |
| Abnormal central microtubular pair morphology of respiratory motile cilia | HP:0012260 | | |
| Abnormal central response of multifocal electroretinogram | HP:0030488 | | |
| Abnormal cervical curvature | HP:0005905 | | |
| Abnormal cervical myelogram | HP:0005788 | | |
| Abnormal cervical spine | HP:0003319 | | |
| Abnormal cholesterol homeostasis | HP:0003464 | | |
| Abnormal ciliary motility | HP:0012262 | | |
| Abnormal circulating aldosterone | HP:0040085 | | |
| Abnormal circulating androgen level | HP:0030347 | | |
| Abnormal circulating creatinine level | HP:0012100 | | |
| Abnormal circulating follicle-stimulating hormone level | HP:0030346 | | |
| Abnormal circulating gonadotropin level | HP:0030338 | | |
| Abnormal circulating insulin level | HP:0040215 | | |
| Abnormal circulating luteinizing hormone level | HP:0030345 | | |
| Abnormal circulating renin | HP:0040084 | | |
| Abnormal class-switched memory B cell count | HP:0030386 | | |
| Abnormal clavicles | HP:0000889 | | |
