Diagnostic strategy for familial and sporadic cases of neuropathy associated with 17p11.2 deletion

Abstract

Clinical, electrophysiologic and molecular studies were performed on at-risk members of 14 families with hereditary neuropathy with liability to pressure palsies (HNPP), in order to detect asymptomatic carriers of the 17p11.2 deletion. Sporadic cases due to de novo deletion accounted for 21% of the investigated HNPP families. Approximately one half of deletion carriers were asymptomatic and did not display significant signs on clinical examination. The electrophysiologic hallmark in both symptomatic and asymptomatic deletion carriers was the presence of a nonuniform sensorimotor demyelinating polyneuropathy with conduction abnormalities preferentially located at common entrapment sites and distal nerve segments. A perfect correlation was found between the molecular and electrophysiologic analyses. A reliable screening method to detect clinically unaffected carriers of the deletion in families with HNPP was the evaluation of motor conduction in at least two nerves across usual entrapment sites, especially the ulnar nerve at the elbow, and evaluation of sensory conduction in the sural nerve. In sporadic cases due to a de novo deletion, electrophysiologic studies were suggestive but not sufficient for the diagnosis, and molecular analysis represented the most sensitive diagnostic tool.

Muscle training‐induced bilateral brachial plexopathy in an adolescent with sporadic hereditary neuropathy with liability to pressure palsies

“…Brachial plexopathy is the third most common clinical phenotype in patients with HNPP following peroneal and ulnar mononeuropathies (Mouton et al., 1999); however, bilateral involvement is unusual (Horowitz et al., 2004; Kim, 2014). Patients sometimes show an atypical clinical phenotype, and a diagnosis of HNPP can therefore be challenging, especially in sporadic cases (Horowitz et al., 2004; Infante et al., 2001), as in our patient.…”

Swallowing dysfunction in hereditary neuropathy with liability to pressure palsies

“…The onset is around the second or third decade of life and 15% of carriers remain asymptomatic 2 . Carriers are predisposed to focal neuropathies that most frequently involve the brachial plexus and peroneal, ulnar, radial, and median nerves 5,12 . Several authors have reported involvement of the facial, trigeminal, hypoglossal and recurrent laryngeal nerves [3][4][5][6][7][8] .…”

Toe Spreading Ability in Men With Chronic Pelvic Pain Syndrome

“…There are familial and sporadic cases with neuropathy associated with genetic abnormalities such as 17p11.2 deletion, forming hereditary neuropathy associated with liability to pressure palsies, and electrophysiologic examinations have shown the presence of conduction abnormalities mostly located at the common entrapment sites [26,27]. Although rarely encountered, the hereditary liability to nerve entrapment syndromes could be among the underlying causes associated with CPPS and should be examined.…”