Vol 8, No 2 (2018)

This prospective clinical and sonographic observation of the 29 y.o. woman with acute neuropathic pain along the course of the radial nerve, who was later diagnosed with hourglass-like focal radial nerve constriction at the level of the inner fold of the elbow. Dynamic observation was carried out at the level of the most severe pain (at the inner fold of the elbow), starting from the 3rd day after onset of symptoms and within 15 months. At the time of patient’s admission pain syndrome and paresis of extensor muscles of the hand and fingers were significantly pronounced, but we didn’t detect any sonographic changes of the radial nerve. During dynamic observation the segment of focal peripheral nerve constriction has been detected on the 30th day of observation and the portion of multisegmental constriction on the 57th day of observation, but the observed changes did not correlate with the rate of neurologic deficit restoration. On the scans of the radial nerve obtained 9 and 15 months after disease onset the uniform decrease in the nerve diameter was evident, which made it impossible to visualize focal peripheral nerve constriction.

Background. Hereditary motor and sensory neuropathies (HMSN) are a genetically diverse group of disorders of the peripheral nerves characterized by gradual development of weakness, muscular hypo-/atrophy, sensory disturbances in distal areas of the extremities. Currently among the recessive forms, the most prevalent HMSN is associated with the ganglioside-induced differentiation associated-protein 1 (GDAP1) gene (GDAP1-HMSN).

The objective is to present an observation of a family case of HMSN type IVA with unusual genealogy.

Materials and methods. Clinical, electrophysiological, and genetic characteristics of a Russian family with GDAP1-HMSN were examined.

Results. We describe a family with autosomal recessive HMSN and unusual genealogy due to homozygous and compound heterozygous mutations of GDAP1.

Conclusion. The particularity of the described family case is the unusual genealogy with the patients in two non-consecutive generations. This type of inheritance is caused by presence of mutations in compound heterozygous state in the proband's grandson which was confirmed by genetic analysis. The presented case demonstrates the importance and necessity of full analysis of the GDAP1 gene or identification of 2 mutations in trans-position in the proband and subsequent assessment of possible risks for future generations. Multiple stroke-like episodes in the 2 affected members of the family are described that have not been previously reported for GDAP1-HMSN. Stroke has been presented in HMSN associated with mitofusin-2 gene which also as GDAP1, affects mitochondrial function in the neurons.