|Year : 2015 | Volume
| Issue : 1 | Page : 66-68
Hunter's syndrome: A case report
NS Savitha, G Saurabh, SH Krishnamoorthy, S Nandan, A Ambili
Department of Pedodontics and Preventive Dentistry, Kurunji Venkatramana Gowda Dental College, Sullia, Karnataka, India
|Date of Web Publication||9-Jan-2015|
Dr. G Saurabh
402/ B Prabhu Apartment, Rajawadi, Ghatkopar (E), Mumbai - 400 077
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Hunter's syndrome or mucopolysaccharidosis (MPS) type II is an X-linked recessive mucopolysaccharide disorder caused by a defect in the metabolism of glycosaminoglycans (GAGs) characterized by involvement of nervous, cardiovascular, respiratory, and mucoskeletal systems along with numerous oral manifestations. This is a case report of a 13-year-old boy referred to the Department of Pediatric Dentistry with a chief complaint of irregularly placed teeth from a general physician. Here we highlight the pivotal role of pediatric dentists in diagnosis and treatment planning for patients diagnosed with such systemic conditions and the provision of advanced dental care in the management of the same.
Keywords: Epilepsy, hunter syndrome, macroglossia, mucopolysaccharides
|How to cite this article:|
Savitha N S, Saurabh G, Krishnamoorthy S H, Nandan S, Ambili A. Hunter's syndrome: A case report. J Indian Soc Pedod Prev Dent 2015;33:66-8
|How to cite this URL:|
Savitha N S, Saurabh G, Krishnamoorthy S H, Nandan S, Ambili A. Hunter's syndrome: A case report. J Indian Soc Pedod Prev Dent [serial online] 2015 [cited 2019 Oct 20];33:66-8. Available from: http://www.jisppd.com/text.asp?2015/33/1/66/149011
| Introduction|| |
Hunter's syndrome or mucopolysaccharidosis (MPS) type II is an X-linked recessive mucopolysaccharide disorder caused by a defect in the metabolism of glycosaminoglycans (GAGs), which results from a deficiency of the enzyme iduronate sulfatase. This results in accumulation of dermatan and heparan sulfates in various tissues. The syndrome is named after physician Charles A Hunter who first described it in 1917. It occurs exclusively in males with a reported incidence of approximately 1 in 170,000 live male births. 
It is a heterogeneous disorder where patients typically have a normal appearance at birth with initial symptoms emerging from 18 months to 4 years of age. There are two forms of Hunter's syndrome based on the length of survival and the presence or absence of central nervous system (CNS) involvement. Type A is the most severe form with a life expectancy of 14-15 years and a much earlier onset. Type B is a much milder form with a life expectancy of 30-50 years and physical features similar to, but not as severe as those of Type A. ,,
The nervous, cardiovascular, respiratory, and mucoskeletal systems can be involved in individuals with Hunter syndrome. The clinical presentation can be divided into two subheadings elaborated in [Table 1]. ,,,,,,,,,
| Case Report|| |
A 13-year-old boy reported to the Department of Pediatric Dentistry with a chief complaint of irregularly placed teeth. The family history revealed a hereditary pattern of the disease with similar features being exhibited in milder degree in patient's younger brother [Figure 1] and [Table 2]. The patient's medical reports correlated with umbilical hernia [Figure 2] and epilepsy indicated towards the diagnosis of Hunter's syndrome. The history of epilepsy is since 7 years of age. The patient was under medication (anticonvulsant) for the same, but discontinued the treatment within a year after and started Ayurvedic treatment. However upon nonimprovement of symptoms, the patient commenced anticonvulsant therapy (2 months back). Epileptic chart was observed and it revealed one to two episodes of seizure every night during sleep. He also got operated for hernia 1 month back. General examination revealed that the child had a short stature, stiff gait, facial asymmetry, macrocephaly, depressed nasal bridge, prominent frontal bulge, narrow nostrils, and broad claw-like short fingers [Figure 3]. Oral manifestations included incompetent lips, macroglossia [Figure 2], high arch palate, anterior open bite, hyperplastic and enlarged gingiva, enlarged adenoid, and thick lips. Intraoral examination also revealed retained deciduous teeth (54, 55, 62, 65, 84, and 85), dental caries in the retained deciduous teeth (65), crossbite with relation to retained deciduous teeth 84 and 85, preshedding mobility with respect to 62, palatally erupted peg lateral incisor (22), Ellis Class II fracture in 11 and 21 [Figure 4], and an unusually prominent oblique ridgein relation to 16 and 26. Panaromic imaging (OPG) revealed resorption of roots in the over-retained primary teeth. The treatment plan was formulated keeping in mind the patient's complaints and the underlying systemic condition. Oral prophylaxis and symptomatic relief with extraction of the over retained teeth was planned after obtaining fitness from the general physician. Written informed consent was taken from the mother prior to beginning the treatment. Oral prophylaxis was done on the firstvisit. On subsequent visits, extraction of the over-retained deciduous teeth was carried out in a quadrant-wise manner.
| Discussion|| |
MPS is a group of lysosomal storage disorders caused by the deficiency of the lysosomal enzymes needed to degrade GAGs. GAGs are oligosaccharide components of proteoglycans which provide structural integrity to the connective tissues. Accumulation of partially degraded GAGs causes thickening of tissue; thereby, leading tocompromise in cell and organ function. This results in permanent, progressive cellular damage which affects the appearance, physical abilities, organ and system functioning and, in most cases, mental development. Hunter syndrome is caused by deficiency of enzyme, iduronate-2-sulfatase (I2s). This leads to an accumulation of incompletely degraded mucopolysaccharides in the lysosomes which affect various body systems through enzymatic activity. All MPS are autosomal recessive, except Hunter syndrome which is X-linked recessive. In affected individuals, undegraded or partially degraded GAG accumulates within the lysosomes and is excreted in excess in the urine. The accumulation of GAG within the lysosomes is responsible for the clinical manifestation of this disorder. Diagnosis of the disease is usually made by clinical presentation and skeletal survey. Thescreening test for MPS type II involves analysis of presence of GAGs (heparan and dermatan sulfates) in urine. The presence of excess heparan and dermatan sulfates in the urine is evidence of MPS type I, MPS type II, or MPS type VII.  Confirmatory diagnosis is made by enzyme assay in leukocytes, fibroblasts or dried blood spots, and plasma sample, using substrates specific for I2s. Absent or low I2s activity in males is diagnostic of Hunter syndrome, provided other sulfatase deficiency has been ruled out. Enzyme replacement therapy using idursulfatase (Elaprase), a recombinant human I2s produced in the human cell line, has been recently approved in the United States and the European Union for the management of MPS type II. Weekly intravenous infusion is given over 3h at a dose of 0.5 mg/kg diluted in saline.  Bone marrow transplantation (BMT) and umbilical cord blood transplantation (UCBT) are definitive treatments for MPS. Apart from these, supportive management is very important. Physical therapy and daily exercise may improve mobility of joints. Blood transfusion, infection, and nutritional management are also important in the management of MPS type II.  Since the disease starts exhibiting various oral symptoms in young age, the role of pediatric dentist is important in recognizing the symptoms, referring the patient for appropriate systemic review with a pediatrician and providing symptomatic relief. The oral health is of paramount importance in these patients as a debilitated general health due to nutritional problems arising out of oral health problems can lead to further deterioration in the patient's general condition.
| Conclusion|| |
Hunter's syndrome is a very serious disease affecting children. Aggressive surgery is usually not advocated for Hunter's syndrome. Pediatric dentist can only provide palliative and therapeutic care for such patients to avoid further untoward complications.
| References|| |
Downs AT, Crisp T, Ferretti G. Hunter's syndrome and oral manifestations: A review. Pediatr Dent 1995;17:98-100.
Dorfman A: Mucopolysaccharidoses. Nelson Textbook of Pediatrics, ll th
ed. Vaughan VC III, McKay RJ Jr, Behrman RE, Eds. Philadelphia: WB Saunders Co, 1979, p. 1845-8.
Gorlin RJ, Cohen MM Jr, Levin LS. Mucopolysaccharidosis II. Syndromes of the Head and Neck. 3 rd
ed. New York: Oxford University Press; 1990. p. 106-8.
LeRoy JG, Crocker AC. Clinical definition of the Hurler-Hunter phenotypes. A review of 50 patients. Am J Dis Child 1966;112:518-30.
Hunter C. A rare disease in two brothers. Proc R Soc Med 1917;10:104-16.
Gardner DG. The oral manifestations of Hurler's syndrome. Oral Surg Oral Med Oral Pathol 1971;32:46-57.
Young ID, Harper PS. The natural history of the severe form of Hunter's syndrome: A study based on 52 cases. Dev Med Child Neurol 1983;25:481-9.
Young ID, Harper PS. Mild form of Hunter's syndrome: Clinical delineation based on 31 cases. Arch Dis Child 1982;57:828-36.
Stewart RE, Prescott GH. Oral facial manifestations of inborn errors of metabolism. Oral Facial Genetics. St Louis: CV Mosby Co; 1976. p. 392-6.
Lustmann J, Bimstein E, Yatziv S. Dentigerous cysts and radiolucent lesions of the jaw associated with Hunter's syndrome. J Oral Surg 1975;33:679-85.
Muenzer J, Beck M, Eng CM, Escolar ML, Giugliani R, Guffon NH, et al
. Multidisciplinary management of hunter syndrome. Pediatrics 2009;124:e1228-39.
Wraith JE, Scarpa M, Beck M, Bodamer OA, De Meirleir L, Guffon N, et al
. Mucopolysaccharidosis type II (Hunter syndrome): A clinical review and recommendations for treatment in the era of enzyme replacement therapy. Eur J Pediatr 2008;167:267-77.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]