Correlation Between Flexible Fiberoptic Laryngoscopic and Polysomnographic Findings in Patients with Mucopolysaccharidosis Type VI

Abstract

This study aimed to compare flexible fiberoptic laryngoscopy (FFL) and polysomnography (PSG) findings in patients with mucopolysaccharidosis (MPS) type VI and to describe upper airway anatomical findings and abnormal PSG results in these patients. In this cross-sectional study, all MPS VI patients followed up at the genetic division of a hospital in southern Brazil were included. Overnight PSG was performed, and the results were classified as normal or mildly, moderately, or severely abnormal. FFL was performed between 7 days before and 7 days after PSG. FFL findings were classified as (1) no obstruction, (2) mild obstruction, (3) moderate obstruction, or (4) severe obstruction of the airways, using the highest score obtained in all the regions.Eleven patients with MPS VI were included. FFL detected severe airway obstruction in eight (72.7%) patients, moderate obstruction in two (18.2%), and mild obstruction in one (9.1%). PSG revealed obstructive sleep apnea syndrome (OSAS) in nine (81.8%) patients. Among these, mild OSAS was observed in five (45.5%) patients, moderate OSAS in three (27.2%), and severe OSAS in one (9.1%). Moderate to severe hypertrophy of the nasal turbinates was found in 81.8% of the patients, and 64% had severe infiltration in the supraglottic region. There was no association between FFL and PSG findings (p ¼ 0.454; k ¼ À0.09; 95%CI ¼ À0.34 to 0.17), indicating no agreement between the two methods. In the present study, all patients with MPS showed some degree of airway obstruction. We suggest performing PSG in MPS patients to determine disease severity.

Assessing the impact of the five senses on quality of life in mucopolysaccharidoses

“…There are several clinical manifestations of MPS that may cause impairments in smell and/or taste, i.e. adenoid hypertrophy, chronic rhinosinusitis, recurrent upper respiratory tract infections, thickened nasal cartilages, macroglossia, dental defects (such as dental caries, gingival inflammation, enamel hypoplasia, unerupted teeth, hyperplastic tooth follicle, anterior open bite, and condylar defects), and possibly neurodegenerative disease [5,[24][25][26]. In addition, continuous upper airway infection can cause chronic production of infected mucus, altering smell and taste.…”

Sleep Disorders in Childhood Neurogenetic Disorders

“…Mucopolysaccharidoses (MPS) are a collection of rare, inherited, lysosomal storage diseases known as Types I–IX. Depending on the specific enzyme deficiency, each type is known by a different name: MPS I as Hurler or Scheie syndrome (OMIM #607014), MPS II as Hunter syndrome (OMIM #309900), MPS III as Sanfillipo syndrome with four subtypes (OMIM #252900, OMIM #252920, OMIM #252930, OMIM #252940), MPS IV as Morquio syndrome (OMIM #253000), MPS VI as Maroteaux-Lamy syndrome (OMIM #253200), MPS VII as Sly syndrome (OMIM #253220), MPS IX as hyaluronidase deficiency (OMIM #601492) [ 77 , 78 , 79 ]. These disorders demonstrate autosomal recessive inheritance with the exception of MPS II, which demonstrates X-linked inheritance [ 79 ].…”

“…These disorders demonstrate autosomal recessive inheritance with the exception of MPS II, which demonstrates X-linked inheritance [ 79 ]. Collectively, they occur once in every 20,000 live births [ 77 , 80 ].…”

“…This causes accumulation of metabolic by-products that lead to cell injury, organ dysfunction, and reduced life expectancy [ 81 ]. Enzyme deficiencies are as follows: MPS I—alpha- l -iduronidase (OMIM #252800), MPS II—iduronate sulfatase (OMIM #300823), MPS III—four types with deficiency in heparan N -sulfatase proteins (OMIM #605270, #609701, #610453 and #607664), MPS IV— N -acetylgalactosamine-6-sulfate sulfatase (OMIM #611458), MPS VI— N -acetylgalactosamine-4-sulfatase deficiency (OMIM #611542), MPS VII—β-glucuronidase (OMIM #611499), MPS IX—hyaluronidase-1 (OMIM #607071) [ 7 , 77 , 78 , 82 , 83 , 84 ]. Due to the heterogeneity of presentation, diagnosis of MPS disorders are made based on clinical features, urinary and tissue GAG levels, enzyme assays, and genetic analysis [ 81 ].…”

“…Specific system involvement is dependent on specific enzyme deficiency but may involve nervous system, musculoskeletal system, heart, liver, lung and airway, and otorhinolaryngologic manifestations. Typical clinical features are characterized by coarse facial features (with protruding or depressed frontal bone, depressed base of the nose, and/or hypoplastic mandible), macroglossia, restricted temporomandibular joint (TMJ) mobility, cognitive impairment, speech and language difficulties, hydrocephalus, spinal cord compression, seizures, frequent sinusitis and respiratory infections, adenotonsillar hypertrophy, airway GAG deposits, disorders of sleep, organomegaly, short stature, scoliosis, gait disturbance, and premature death in the second or third decade of life [ 7 , 77 , 80 , 81 , 82 , 85 , 86 ].…”