Mannosidosis

Autosomal recessive transmission.

Deficiency in mannosidase (lysosomal enzyme) that causes an accumulation of mannose-rich oligosaccharides in in the nervous tissues and viscera.

Several types:

α-mannosidosis [MIM 248 500]: deficiency in α-mannosidase (MAN2B1 gene on 19p13.2-q12)

o type I: mild form, generally diagnosed after the age of 10 years: slow progress and lack of bone deformities;

o type II: moderate form: onset before 10 years of age with bone deformities: multiple dysostosis, scoliosis, sternal deformation; slow progression of mental retardation and ataxia around the age of 20-30 years; hearing problems, sometimes episodes of psychosis

o type III: severe form: early diagnosis because the clinical signs are rapidly progressive and similar to Hurler disease; pes equinovarus, hydrocephalus; facial dysmorphism: broad head with prominent forehead, flattened nasal bridge, macroglossia, prognathism; deaths in childhood.

β-mannosidosis [MIM 248 510]: very rare; deficit in β-mannosidase (chromosome 4q25-q22); neurological and mental disorders, auditory problems, speech retardation, swallowing disorders (achalasia).

An increased susceptibility to infection by immunodeficiency is frequent and early in both forms.

Treatment: early bone marrow transplantation for the α-mannosidosis.

Anesthetic implications:

according to the patient’s sequelae. Risk of difficult intubation in cases of dysmorphism similar to Hurler disease. No observed ventilation or intubation difficulties (type II ?) in a series of patients aged 7 to 17 years. Care of a deaf patient with variable mental retardation. Frequent immunodeficiency.

References:

- Hallas P, Bordwards LG, Roed J, Dali CI, Lund AM.
Anesthesia for patients with alpha-mannosidosis : a case series of 10 patients.
Pediatr Anesth 2011; 21: 1269-70.

- Yesilipek AM, Akcan M, Karasu G, Uygum V et al.
Successful unrelated bone marrow transplantation in two siblings with alpha-mannosidosis.
Pediatr Transplantation 2012; 16: 779-82.

Updated: January 2019