I-cell Disease Research Articles

Unlocking the Enigma: Investigating I-Cell Disease in a Newborn Through Placental Pathology.

I-cell disease (Mucolipidosis Type II) is a rare lysosomal storage disorder caused by GNPTAB gene defects, leading to severe morbidity and mortality. The authors present the case of a neonate born at 38 wk gestational age, with suspected skeletal dysplasia during pregnancy and a complex clinical and laboratory presentation after birth. This is a rare case, and its diagnosis was made through placental pathology, which revealed the condition called mucolipidosis Type II. To the best of authors' knowledge, this is one of the few cases diagnosed in the neonatal period with placental pathology globally and the first in Canada, highlighting the significance of placental pathology for the diagnosis of these rare conditions and future counseling of the parents. In conclusion, mucolipidosis Type II is a rare condition in neonates. Early diagnosis in neonates can be made through placental pathology for parental counseling.

Outcomes after HSCT for mucolipidosis II (I-cell disease) caused by novel compound heterozygous GNPTAB mutations.

Mucolipidosis type II (MLII), or I-cell disease, is a rare lysosomal storage disease (LSD) caused by variants in the GNPTAB gene. MLII patients exhibit clinical phenotypes in the prenatal or neonatal stage, such as marked dysmorphic features, cardiac involvement, respiratory symptoms, dysostosis multiplex, severe growth abnormalities, and mental and motor developmental abnormalities. The median age at diagnosis for MLII is 0.7 years, the median survival is 5.0 years, and the median age at death is 1.8 years. No cure for MLII exists. Sanger sequencing of the GNPTAB gene identified the compound heterozygous mutations c.673C > T in exon 7 and c.1090C > T in exon 9, which were novel double heterozygous mutations first reported in China. For the first time, we describe our experience in the use of HSCT for MLII. Our patient underwent HSCT with cells from a 9/10 human leukocyte antigen (HLA)-matched unrelated donor at 12 months of age. Myeloid neutrophil and platelet engraftment occurred on Days 10 and 11, respectively. The patient's limb muscle tension was significantly reduced, and his gross and fine motor skills were improved four months after transplantation. DST(Developmental Screen Test) results showed that the patient's fine motor skills and mental development were improved compared with before HSCT. MLII is a very severe lysosomal storage disease, to date, only 3 cases have been reported on the use of HSCT to treat MLII. Our data show that HSCT is a potential way to prolong the life of patients and improve their quality of life. Due to the lack of comparable data and time, the exact benefit remains unclear in MLII patients. Longer-term follow-up and in-depth prospective studies are indispensable.

The human disease gene LYSET is essential for lysosomal enzyme transport and viral infection.

Lysosomes are key degradative compartments of the cell. Transport to lysosomes relies on GlcNAc-1-phosphotransferase-mediated tagging of soluble enzymes with mannose 6-phosphate (M6P). GlcNAc-1-phosphotransferase deficiency leads to the severe lysosomal storage disorder mucolipidosis II (MLII). Several viruses require lysosomal cathepsins to cleave structural proteins and thus depend on functional GlcNAc-1-phosphotransferase. We used genome-scale CRISPR screens to identify lysosomal enzyme trafficking factor (LYSET, also named TMEM251) as essential for infection by cathepsin-dependent viruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). LYSET deficiency resulted in global loss of M6P tagging and mislocalization of GlcNAc-1-phosphotransferase from the Golgi complex to lysosomes. Lyset knockout mice exhibited MLII-like phenotypes, and human pathogenic LYSET alleles failed to restore lysosomal sorting defects. Thus, LYSET is required for correct functioning of the M6P trafficking machinery and mutations in LYSET can explain the phenotype of the associated disorder.

Secondary Hyperparathyroidism in Children with Mucolipidosis Type II (I-Cell Disease): Irish Experience.

Mucolipidosis type II (ML II) is an autosomal recessive lysosomal targeting disorder that may present with features of hyperparathyroidism. The aim of this study was to describe in detail the clinical cases of ML II presenting to a tertiary referral centre with biochemical and/or radiological features of hyperparathyroidism. There were twenty-three children diagnosed with ML II in the Republic of Ireland from July 1998 to July 2021 inclusive (a 23-year period). The approximate incidence of ML II in the Republic of Ireland is, therefore, 1 per 64,000 live births. Medical records were available and were reviewed for 21 of the 23 children. Five of these had been identified as having biochemical and/or radiological features of hyperparathyroidism. Of these five, three children were born to Irish Traveller parents and two to non-Traveller Irish parents. All five children had radiological features of hyperparathyroidism (on skeletal survey), with evidence of antenatal fractures in three cases and an acute fracture in one. Four children had biochemical features of secondary hyperparathyroidism. Three children received treatment with high dose Vitamin D supplements and two who had antenatal/acute fractures were managed with minimal handling. We observed resolution of secondary hyperparathyroidism in all cases irrespective of treatment. Four of five children with ML II and hyperparathyroidism died as a result of cardiorespiratory failure at ages ranging from 10 months to 7 years. Biochemical and/or radiological evidence of hyperparathyroidism is commonly identified at presentation of ML II. Further studies are needed to establish the pathophysiology and optimal management of hyperparathyroidism in this cohort. Recognition of this association may improve diagnostic accuracy and management, facilitate family counseling and is also important for natural history data.

50 Years Ago in TheJournalofPediatrics: I-Cell Disease: The More Things Change, the More They Stay the Same

50 Years Ago in TheJournalofPediatrics: I-Cell Disease: The More Things Change, the More They Stay the Same

Lysosomal Storage Disorders: Clinical, Biochemical and molecular profile from Rare disease centre, India.

Introduction:Lysosomal storage disorders (LSDs) are a heterogeneous group of large molecule inborn errors of metabolism, rather commonly seen by clinician.Objectives:This study aims to highlight the more common type of LSDs, their frequency, clinical spectrum and outcome from Rare disease centre in Rajasthan.Methods:The retrospective data were collected including clinical profile, investigations, screening test and enzyme analysis results. All outcomes were recorded from follow-up clinic.Results:This cohort comprised 65 children with different type of LSDs including 54 males and 11 females. The average age of presentation of the LSD patients was 3.5 years (range 6 months to 13 years). Gaucher disease was the most commonly found LSD (46.1%) followed by mucopolysaccharidosis (35.3%). Common presentations among GD patients were anemia, thrombocytopenia, and abdominal distension due to splenohepatomegaly/hepatomegaly. Among MPS Disorder, MPS type 2 (Hunter syndrome) was the most common (39.1%), followed by MPS type 1(Hurler syndrome) (30%) and MPS type IVA (Morquio syndrome) (17.3%). Non GD non MPS group comprised most commonly of GM1 gangliosidosis followed by pompe disease, Metachromatic Leucodystrophy, Mucolipidosis type II (I cell disease), and Sandhoff disease.Conclusions:LSDs comprises an important group of genetic metabolic disorders. Among these GD are the most common, followed by MPS.

Lizozomal Depo Hastalıkları: Kırıkkale Üniversitesi Deneyimi

Objective: Lysosomal storage diseases which were first described in 1880; are important group of metabolic disorders characterized by the deposition of the substrates in lysosomes due to defects of the activity or transport of lysosomal enzymes or a defect in the receptor proteins. LSDs usually show a progressive clinical course and may not be represented with any clinical signs during the neonatal period. The overall prevalence of LSDs is 1 / 7000-8000. The aim of this study was to share the clinical characteristics of our LSDs patients and the experiences of our pediatric metabolic diseases department.Material and Methods: This retrospective cohort study was conducted at Kırıkkale University Hospital with 56 patients diagnosed as lysosomal storage disease among 315 patients diagnosed with metabolic diseases. Data were collected from outpatient clinic patient files who were diagnosed between 2011- 2018. Results: A total of 315 patients diagnosed with inherited metabolic disease were followed in our clinic and 56 (17.7 %) of them were diagnosed as LSDs. The 56 patients were suffering from the following diseases: 10 patients with Mucopolysaccharidosis, 1 patient with mucolipidosis type 2 (I-cell disease), 41 patients with sphingolipidoses, two patients with cystinosis, one patient with Infantile Pompe Disease and one patient with beta-mannosidosis.The mean age of the patients with Fabry Disease and the other patients diagnosed with other LSDs were 34.7±14.2 years (minimum 8, maximum 64) and 2.67±3.4 years (minimum 0, maximum 10.5) respectively. All diagnoses were verified by specific enzyme analysis and/or by conducting genetic mutation analysis. Conclusion: The most common lysosomal storage disease among our patients were Mucopolysaccharidosis and sphingolipidosis. Treatment options, such as enzyme replacement therapy and bone marrow transplantation exist, and 24 of these patients are receiving enzyme replacement therapy.

Comorbid Cardiovascular Malformation and Type II Mucolipidosis: Clinical Case

Background . Type II mucolipidosis (I-cell disease, ICD) is one of the lysosomal storage diseases. It is very rare disease; the literature describes only few cases with confirmed diagnosis of mucolipidosis. Cardiovascular changes in children with such pathology are even less often. Clinical case description . The article describes the clinical case of type II mucolipidosis alongside with cardiovascular pathology — valvular heart apparatus defect with abdominal aortic hypoplasia and reversible myocardial dysfunction on the therapy of chronic heart failure (CHF). The patient has coarse face, gingival hyperplasia, macroglossia, dysostosis multiplex, diffuse muscular hypotonia, and mass of subcutaneous tissue. Arterial hypertension, heart cavities dilatation, left ventricular (LV) walls hypertrophy, and data of CT aortography let us to diagnosis abdominal aortic hypoplasia. Conclusion . Cardiovascular malformation in patients with mucolipidosis leads to severe, life-threatening conditions development. Untimely diagnosis can worsen the course of disease. Multidisciplinary approach is needed for the patient management.

Inappropriate cathepsin K secretion promotes its enzymatic activation driving heart and valve malformation.

Although congenital heart defects (CHDs) represent the most common birth defect, a comprehensive understanding of disease etiology remains unknown. This is further complicated since CHDs can occur in isolation or as a feature of another disorder. Analyzing disorders with associated CHDs provides a powerful platform to identify primary pathogenic mechanisms driving disease. Aberrant localization and expression of cathepsin proteases can perpetuate later-stage heart diseases, but their contribution toward CHDs is unclear. To investigate the contribution of cathepsins during cardiovascular development and congenital disease, we analyzed the pathogenesis of cardiac defects in zebrafish models of the lysosomal storage disorder mucolipidosis II (MLII). MLII is caused by mutations in the GlcNAc-1-phosphotransferase enzyme (Gnptab) that disrupt carbohydrate-dependent sorting of lysosomal enzymes. Without Gnptab, lysosomal hydrolases, including cathepsin proteases, are inappropriately secreted. Analyses of heart development in gnptab-deficient zebrafish show cathepsin K secretion increases its activity, disrupts TGF-β–related signaling, and alters myocardial and valvular formation. Importantly, cathepsin K inhibition restored normal heart and valve development in MLII embryos. Collectively, these data identify mislocalized cathepsin K as an initiator of cardiac disease in this lysosomal disorder and establish cathepsin inhibition as a viable therapeutic strategy.

MANAGEMENT CONSIDERATIONS FOR RESPIRATORY COMPLICATIONS IN THOSE WITH MUCOLIPIDOSIS TYPE II (I-CELL DISEASE)

SESSION TITLE: Medical Student/Resident Genetic and Developmental Disorders Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Mucolipidosis type II (I-cell disease) is an autosomal recessive lysosomal storage disease resulting from N-acetylglucosamine-1-phosphotransferese deficiency. Affected children have multiple skeletal abnormalities and recurrent respiratory infections [1, 2]. Despite evidence for respiratory compromise in affected children, there is a paucity of literature on the management of respiratory complications. We present a patient with I-cell disease admitted for respiratory failure resulting from pneumonia. CASE PRESENTATION: A 20 month-old female with I-cell disease presented with four days of fever, productive cough, and respiratory difficulties. Vital signs were remarkable for a fever of 40.6 Celsius and hypoxia with an oxygen saturation of 73%. Patient required 25 L/min of supplemental oxygen via high-flow nasal cannula (HFNC) to maintain an adequate saturation. Physical exam revealed an infant in severe respiratory distress with diffuse rhonchi. Work-up was positive for Influenza B and a chest radiograph (CXR) revealed patchy left lung opacities [Figure 1A]. Patient started on ceftriaxone, fluids, and oseltamivir. Over the next 48 hours she clinically improved and was weaned to 2 L of oxygen. However, on hospital day three, the patient developed intermittent fevers, and increased work of breathing requiring re-initiation of HFNC. Repeat CXR demonstrated worsening opacification [Figure 1B]. Given these findings the patient’s antibiotic regimen was broadened to vancomycin and cefepime to provide coverage for Pseudomonas spp. The patient improved rapidly and was weaned off of supplemental oxygen. She subsequently was discharged home with oral clindamycin and levofloxacin. DISCUSSION: Recurrent respiratory infections are common in patients with I-cell disease. Factors such as increased secretions and abnormal airway architecture contribute to the chronic sino-pulmonary infections, poor bacterial clearance, and respiratory compromise [2]. An autopsy case performed on a patient with I-cell disease identified the presence of aberrant type II pneumocytes, which suggests that there may be an inherent immune dysregulation in those with I-cell disease [3]. This inherent immune dysregulation may be why those with I-cell disease are predisposed to complicated, multi-drug resistant (MDR) pulmonary infections. CONCLUSIONS: Clinicians caring for patients with I-cell disease who are admitted for pneumonia should consider early initiation of broad-spectrum empiric antibiotics, specifically with coverage for Pseudomonas spp. Further studies are needed to clarify if patients with I-cell disease have impaired respiratory immunity, which augments the growth of MDR bacteria in the lung. Reference #1: Faverio P, Stainer A, De Giacomi F, Gasperini S, Motta S, Canonico F, Pieruzzi F, Monzani A, Pesci A, Biondi A. Molecular Pathways and Respiratory Involvement in Lysosomal Storage Diseases. Int J Mol Sci. 2019 Jan 15;20(2). pii: E327 Reference #2: Mallen J, Highstein M, Smith L, Cheng J. Airway management considerations in children with I-cell disease. Int J Pediatr Otorhinolaryngol. 2015 May;79(5):760-2 Reference #3: Sato Y, Kobayashi H, Sato S, Shimada Y, Fukuda T, Eto Y, Ohashi T, Ida H. Systemic accumulation of undigested lysosomal metabolites in an autopsy case of mucolipidosis type II; autophagic dysfunction in cardiomyocyte. Mol Genet Metab. 2014 Jul;112(3):224-8. DISCLOSURES: No relevant relationships by Ethan Karle, source=Web Response No relevant relationships by Armin Krvavac, source=Web Response No relevant relationships by Michael Nance, source=Web Response No relevant relationships by Tarang Patel, source=Web Response

Upregulation of Sortilin, a Lysosomal Sorting Receptor, Corresponds with Reduced Bioavailability of Latent TGFβ in Mucolipidosis II Cells.

Mucolipidosis II (ML-II) is a lysosomal disease caused by defects in the carbohydrate-dependent sorting of soluble hydrolases to lysosomes. Altered growth factor signaling has been identified as a contributor to the phenotypes associated with ML-II and other lysosomal disorders but an understanding of how these signaling pathways are affected is still emerging. Here, we investigated transforming growth factor beta 1 (TGFβ1) signaling in the context of ML-II patient fibroblasts, observing decreased TGFβ1 signaling that was accompanied by impaired TGFβ1-dependent wound closure. We found increased intracellular latent TGFβ1 complexes, caused by reduced secretion and stable localization in detergent-resistant lysosomes. Sortilin, a sorting receptor for hydrolases and TGFβ-related cytokines, was upregulated in ML-II fibroblasts as well as GNPTAB-null HeLa cells, suggesting a mechanism for inappropriate lysosomal targeting of TGFβ. Co-expression of sortilin and TGFβ in HeLa cells resulted in reduced TGFβ1 secretion. Elevated sortilin levels correlated with normal levels of cathepsin D in ML-II cells, consistent with a compensatory role for this receptor in lysosomal hydrolase targeting. Collectively, these data support a model whereby sortilin upregulation in cells with lysosomal storage maintains hydrolase sorting but suppresses TGFβ1 secretion through increased lysosomal delivery. These findings highlight an unexpected link between impaired lysosomal sorting and altered growth factor bioavailability.

Disease-causing missense mutations within the N-terminal transmembrane domain of GlcNAc-1-phosphotransferase impair endoplasmic reticulum translocation or Golgi retention.

Transport of newly synthesized lysosomal enzymes to the lysosome requires tagging of these enzymes with the mannose 6-phosphate moiety by UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase), encoded by two genes, GNPTAB and GNPTG. GNPTAB encodes the α and β subunits, which are initially synthesized as a single precursor that is cleaved by Site-1 protease in the Golgi. Mutations in this gene cause the lysosomal storage disorders mucolipidosis II (MLII) and mucolipidosis III αβ (MLIII αβ). Two recent studies have reported the first patient mutations within the N-terminal transmembrane domain (TMD) of the α subunit of GlcNAc-1-phosphotransferase that cause either MLII or MLIII αβ. Here, we demonstrate that two of the MLII missense mutations, c.80T>A (p.Val27Asp) and c.83T>A (p.Val28Asp), prevent the cotranslational insertion of the nascent GlcNAc-1-phosphotransferase polypeptide chain into the endoplasmic reticulum. The remaining four mutations, one of which is associated with MLII, c.100G>C (p.Ala34Pro), and the other three with MLIII αβ, c.70T>G (p.Phe24Val), c.77G>A (p.Gly26Asp), and c.107A>C (p.Glu36Pro), impair retention of the catalytically active enzyme in the Golgi with concomitant mistargeting to endosomes/lysosomes. Our results uncover the basis for the disease phenotypes of these patient mutations and establish the N-terminal TMD of GlcNAc-1-phosphotransferase as an important determinant of Golgi localization.

Spectrum of Lysosomal Storage Disorders at Tertiary Centre: Retrospective Case-Record Analysis.

Lysosomal storage disorders (LSDs) are relatively common slow progressive inborn error of metabolism encountered by clinicians. This work intends to highlight the more common LSDs, their clinical presentation, outcome, and mutation (wherever feasible) collected from the genetic clinic at tertiary care center in Eastern Uttar Pradesh. The data for analysis were collected retrospectively from genetic records from a follow-up clinic. All cases < 18 years of age were analyzed. Cases with LSDs with confirmed enzyme results were enrolled in this study. Clinical profile, screening test results, and outcome were collected. There were 32 cases including 27 males and 5 females in this cohort: 8 Gaucher disease (GD) patient and 24 non-GD patients. GD (type 1) is the commonest LSD in GD group. Anemia, thrombocytopenia, splenomegaly, and hepatomegaly were the consistent finding in patients with GD (type 1). L483P mutation was reported in two GD patients. One GD patient is on enzyme replacement therapy for 2 years and is currently doing well. The commonest disorders in non-GD were mucopolysaccharidosis (MPS) ( n = 11), metachromatic leukodystrophy ( n = 4), I-cell disease ( n = 3), Niemann-Pick A/B ( n = 3). MPS-II is the commonest MPS among non-GD group.

Characterization of mesenchymal stem cells in mucolipidosis type II (I-cell disease).

Mucolipidosis type II (ML-II, I-cell disease) is a fatal inherited lysosomal storage disease caused by a deficiency of the enzyme N-acetylglucosamine-1-phosphotransferase. A characteristic skeletal phenotype is one of the many clinical manifestations of ML-II. Since the mechanisms underlying these skeletal defects in ML-II are not completely understood, we hypothesized that a defect in osteogenic differentiation of ML-II bone marrow mesenchymal stem cells (BM-MSCs) might be responsible for this skeletal phenotype. Here, we assessed and characterized the cellular phenotype of BM-MSCs from a ML-II patient before (BBMT) and after BM transplantation (ABMT), and we compared the results with BM-MSCs from a carrier and a healthy donor. Morphologically, we did not observe differences in ML-II BBMT and ABMT or carrier MSCs in terms of size or granularity. Osteogenic differentiation was not markedly affected by disease or carrier status. Adipogenic differentiation was increased in BBMT ML-II MSCs, but chondrogenic differentiation was decreased in both BBMT and ABMT ML-II MSCs. Immunophenotypically no significant differences were observed between the samples. Interestingly, the proliferative capacity of BBMT and ABMT ML-II MSCs was increased in comparison to MSCs from age-matched healthy donors. These data suggest that MSCs are not likely to cause the skeletal phenotype observed in ML-II, but they may contribute to the pathogenesis of ML-II as a result of lysosomal storage-induced pathology.

A GNPTAB nonsense variant is associated with feline mucolipidosis II (I-cell disease)

BackgroundMucolipidosis II (ML II; I-cell disease) is caused by a deficiency of N-acetylglucosamine-1-phosphotransferase (GNPTAB; EC 2.7.8.17), which leads to a failure to internalize acid hydrolases into lysosomes for proper catabolism of various substances. This is an autosomal recessive lysosomal storage disease and causes severe progressive neuropathy and oculoskeletal dysfunction in humans (OMIM 252500). A naturally occurring disease model has been reported in juvenile domestic cats (OMIA 001248–9685) with clinical signs similar to human patients. We investigated the molecular genetic basis of ML II in a colony of affected cats by sequencing the coding and regulatory regions of GNPTAB from affected and clinically healthy related and unrelated domestic cats and compared the sequences to the published feline genome sequence (NCBI-RefSeq accession no. XM_003989173.4, Gene ID: 101100231).ResultsAll affected cats were homozygous for a single base substitution (c.2644C > T) in exon 13 of GNPTAB. This variant results in a premature stop codon (p.Gln882*) which predicts severe truncation and complete dysfunction of the GNPTAB enzyme. About 140 GNPTAB variants have been described in human ML II patients, with 41.3% nonsense/missense mutations, nine occurring in the same gene region as in this feline model. Restriction fragment length polymorphism and allelic discrimination real-time polymerase chain reaction assays accurately differentiated between clear, asymptomatic carriers and homozygous affected cats.ConclusionMolecular genetic characterization advances this large animal model of ML II for use to further define the pathophysiology of the disease and evaluate novel therapeutic approaches for this fatal lysosomal storage disease in humans.

Electron Microscopy Can Still Have a Role in the Diagnosis of Selected Inborn Errors of Metabolism.

Many anatomic pathology laboratories no longer have electron microscopy facilities. A retrospective review of autopsies was performed to identify cases of inborn errors of metabolism (IEM) and determine the contribution of electron microscopy in making the diagnosis in those cases. Over a period of 17 years, there were 900 perinatal and pediatric autopsies. There were 7 cases (1%) of IEM, including 4 cases of Pompe disease, 1 case of I-cell disease, 1 case of bile acid synthesis defect, and 1 case of mitochondrial disease (Leigh syndrome). Electron microscopy was important in the diagnosis of I-cell disease and Pompe disease in our series. This technique enabled a prenatal diagnosis to be made from a chorionic villus biopsy in 2 cases with a positive family history. In less developed countries where upfront genetic testing may be too expensive and may need international referral, electron microscopy can still be useful for diagnosis of IEM, providing an affordable alternative with a more rapid turnaround time compared to gene mutation analysis or enzyme assay. Results can be used both for patient management and as a screen for which cases might benefit from genetic testing.

Inclusion Cell Disease - A Rare Cause of Megalocornea with Corneal Edema

Inclusion cell disease (I cell disease), also known as mucolipidosis type II, is a rare congenital metabolic storage disorder which seemingly occupies an intermediate position between mucopolysaccharidosis and sphingolipidosis.1 We are hereby presenting a case of I cell disease that presented with megalocornea and corneal edema/corneal clouding.

I-Cell Disease (Mucolipidosis II): A Case Series from a Tertiary Paediatric Centre Reviewing the Airway and Respiratory Consequences of the Disease.

Inclusion cell disease (I-cell) is a rare autosomal recessive metabolic disease involving multiple organ systems, associated with a severely restricted life expectancy. No curative therapy is currently available, with management aimed at symptom palliation. We present a retrospective, single-centre, case series of children referred to a tertiary paediatric metabolic service. The clinical presentation, demographics, genetics and natural history of the condition are investigated. Five patients with I-cell disease were referred over a 10-year period. All patients were born with dysmorphic features and had a family history of I-cell disease on further exploration. Phenotypic variation was seen within patients with the same genetic profile. Airway problems were common with 100% of the documented sleep oximetry studies suggesting sleep-disordered breathing. Of the two patients who had tracheal intubation anaesthetic difficulties we encountered, one required intraoperative reintubation, and one suffered a failed intubation with subsequent death. All five patients required oxygen therapy with the use of CPAP and BiPAP also seen. Feeding issues were almost universal with four of the five patients requiring nasogastric feeding. Four patients had died in the 10-year period with a mean life expectancy of 36months. Cause of death for three of the four patients was respiratory failure. Airway problems, including sleep-disordered breathing, were ubiquitous in this cohort of children. Any intervention requiring a general anaesthetic needs careful multidisciplinary consideration due to significant associated risks and possibly death. Management as a result is generally non-surgical and symptomatic. This case series demonstrates universal involvement of the airway and respiratory systems, an important consideration when selecting meaningful outcomes for future effectiveness studies of novel therapies.

I-Cell Disease with GNPTAB Gene Mutation

I-cell disease is a rare inherited metabolic disorder resulting from a defective phosphotransferase, characterized by coarse facial features, skeletal abnormalities and mental retardation. As clinical features of this condition mimic that of Hurler disease mutation studies help in the diagnosis. We present a case of I-cell disease in a neonate with GNPTAB gene mutation.

Anesthetic Management of a 13-Year-Old Adolescent With Mucolipidosis Type II for Total Hip Arthroplasty

Mucolipidosis II (ML II) or inclusion cell disease is a rare lysosomal storage disorder, inherited as an autosomal recessive trait. Deficiency of the lysosomal transport enzyme, N-acetylglucosamine-1-phosphotransferease, results in the intracellular accumulation of macromolecules (mucopolysaccharides and mucolipids) in the lysosome which leads to cellular dysfunction and a multi-system disorder. Manifestations are present at birth including muscle hypotonia, a weak cry, and failure to thrive. Additional physical signs include hip dislocation, inguinal hernia, hepatomegaly, limitation of joint movement, and cutaneous changes. Coarse facial features and skeletal abnormalities become more conspicuous with time. A rapidly progressive psychomotor deterioration, developmental delay and growth failure are often noted with a limited life span of 10 years. Due to the aforementioned physical abnormalities, surgical and anesthetic care may be required. We present a 13-year-old girl with ML II who required anesthetic care for a total hip arthroplasty due to chronic right hip dislocation. Previous reports of anesthetic care for these patients are reviewed, end-organ involvement is discussed, and options for anesthetic care are presented. J Med Cases. 2017;8(7):203-206 doi: https://doi.org/10.14740/jmc2834w