Diarrhea and autonomic dysfunction in a patient with hexosaminidase B deficiency (Sandhoff disease)

Natural History of Adult Patients with GM2 Gangliosidosis

OBJECTIVE

GM2 gangliosidoses are lysosomal diseases due to biallelic mutations in the HEXA (Tay-Sachs disease [TS]) or HEXB (Sandhoff disease [SD]) genes, with subsequent low hexosaminidase(s) activity. Most patients have childhood onset, but some experience the first symptoms during adolescence/adulthood. This study aims to clarify the natural history of adult patients with GM2 gangliosidosis.

METHODS

We retrospectively described 12 patients from a French cohort and 45 patients from the literature.

RESULTS

We observed 4 typical presentations: (1) lower motoneuron disorder responsible for proximal lower limb weakness that subsequently expanded to the upper limbs, (2) cerebellar ataxia, (3) psychosis and/or severe mood disorder (only in the TS patients), and (4) a complex phenotype mixing the above 3 manifestations. The psoas was the first and most affected muscle in the lower limbs, whereas the triceps and interosseous were predominantly involved in the upper limbs. A longitudinal study of compound motor action potentials showed a progressive decrease in all nerves, with different kinetics. Sensory potentials were sometimes abnormally low, mainly in the SD patients. The main brain magnetic resonance imaging feature was cerebellar atrophy, even in patients without cerebellar symptoms. The prognosis was mainly related to gait disorder, as we showed that beyond 20 years of disease evolution, half of the patients were wheelchair users.

INTERPRETATION

Improved knowledge of GM2 gangliosidosis in adults will help clinicians achieve correct diagnoses and better inform patients on the evolution and prognosis. It may also contribute to defining proper outcome measures when testing emerging therapies. ANN NEUROL 2020;87:609-617.

Late-onset Tay-Sachs disease: the spectrum of peripheral neuropathy in 30 affected patients

Late-onset Tay-Sachs (LOTS) disease is a chronic, progressive, lysosomal storage disorder caused by a partial deficiency of beta-hexosaminidase A (HEXA) activity. Deficient levels of HEXA result in the intracellular accumulation of GM2-ganglioside, resulting in toxicity to nerve cells. Clinical manifestations primarily involve the central nervous system (CNS) and lower motor neurons, and include ataxia, weakness, spasticity, dysarthria, dysphagia, dystonia, seizures, psychosis, mania, depression, and cognitive decline. The prevalence of peripheral nervous system (PNS) involvement in LOTS has not been well documented, but it has traditionally been thought to be very low. We examined a cohort of 30 patients with LOTS who underwent clinical and electrophysiologic examination, and found evidence of a predominantly axon loss polyneuropathy affecting distal nerve segments in the lower and upper extremities in eight patients (27%).

Dysautonomic achalasia in two siblings with Sandhoff disease

Two siblings in their sixth decade with chronic Type II GM2 gangliosidosis developed progressive dysphagia in addition to chronic motor neuron disease and autonomic nervous system (ANS) involvement. Esophageal achalasia was diagnosed in both patients. It is suggested that this esophageal motor disorder may be a manifestation of the neurovegetative system disorder due to alteration of ganglioside metabolism.

Peripheral and autonomic nervous system involvement in chronic GM2-gangliosidosis

GM2-gangliosidosis (McKusick 268800 and 272800) is a rare hereditary, progressive disorder of ganglioside metabolism caused by deficiency of lysosomal beta-hexosaminidase (EC 3.2.1.52) activity. It is characterized by severe central nervous system involvement. Involvement of the peripheral and autonomic nervous system has been suspected but rarely documented in published case reports in the chronic form of the disease. Four patients, aged 24-29 years, with chronic GM2-gangliosidosis were examined prospectively for evidence of peripheral and autonomic nervous system dysfunction. All had nerve conduction studies, sympathetic skin responses and cardiac monitoring during the head tilt-table test. Three patients had objective evidence of autonomic dysfunction with abnormal sympathetic nervous skin responses and axonal sensorimotor polyneuropathy. None of the patients had evidence of significant cardiovascular autonomic dysfunction on the head tilt-table test. The peripheral and autonomic nervous system may be involved in patients with chronic GM2-gangliosidosis. In some cases, this may be clinically significant. On the other hand, cardiovascular autonomic instability is apparently not a significant problem in young adult patients with the disease.

Perinatal exposure to measles virus is not associated with the development of inflammatory bowel disease

It has been suggested that early exposure to measles virus, including perinatal exposure via maternal infection, may lead to persistent measles virus infection and the subsequent development of inflammatory bowel disease (IBD). We sought to examine this association in our patient population. Maternal measles infection was identified through the Mayo Clinic diagnostic index, and cases were verified by chart review. Cases were included if infection occurred between the second trimester and 6 months postpartum. The offspring, or a first degree family member, were then interviewed regarding a history of IBD or symptoms which might suggest IBD. Seven cases of maternal infection were identified out of 67,912 pregnancies between 1935 and 1985. One offspring was lost to follow-up through adoption, and the remaining six have no evidence of Crohn's disease or ulcerative colitis after a mean of 38 years of follow-up (range 12-62 years). Evidence for an association between perinatal exposure to measles virus via maternal infection and the subsequent development of IBD was not found in our patient population.

Evaluation of the adult patient with diarrhea

This article provides the primary care clinician with a general diagnostic and therapeutic approach to the adult patient with diarrhea. Basic pathophysiologic mechanisms are described. Important causes and clinical features of each type of diarrhea are highlighted. A step-by-step diagnostic evaluation is suggested, and an overview of treatment options is presented.