Table 2 Classification of hereditary sensory neuropathies type I (HSN I)
Subtype | Hallmark/additional features | Locus | Gene | OMIM # |
|---|---|---|---|---|
HSN IA | Predominant loss of pain and temperature sensation, sometimes initial sign with long preservation of vibration sense, burning and lancinating pain, variable distal motor involvement, which may be severe. | 9q22.1–q22.3 | SPTLC1 | 162400 |
HSN IB | Predominant sensory neuropathy with cough and gastro-oesophageal reflux, rarely foot ulcerations; normal distal muscle strength. | 3p24–p22 | unknown | 608088 |
HSN IC (= CMT2B, HMSN IIB) | Prominent distal motor involvement, often as initial sign of the disease, sensory loss of all qualities, acro-mutilating complications. | 3q21 | RAB7 | 600882 |
HSN ID | Prominent sensory loss and mutilations in hands and feet, acropathy; variable motor involvement. | unknown | unknown | - |