Morquio syndrome is a subtype of mucopolysaccharidoses, wherein the accumulation of glycosaminoglycans (GAGs) in various organ systems lead to alteration of anatomy and physiology. Most prominent features are extensive bony abnormalities, which normally require surgical correction. This paper reports the case of a 7-year-old child with Morquio syndrome who successfully underwent correction of genu valgum under general endotracheal anesthesia via asleep induction and videolaryngoscopy, with supplemental peripheral nerve block. The precautions and anesthetic care done to ensure a safe procedure are discussed, especially with anticipation of a possible difficult airway.
Mucopolysaccharidosis IV ; Mucopolysaccharidoses ; Anesthesia

Consensus ; Humans ; Mucopolysaccharidoses/therapy* ; Mucopolysaccharidosis IV ; Mucopolysaccharidosis VI

Child ; Female ; Humans ; Male ; Mucopolysaccharidosis IV ; genetics ; Mutation ; N-Acetylgalactosamine-4-Sulfatase ; genetics

Morquio's syndrome is a very rare disease, which is characterized by dwarfism, flattening of the vertebral body, marked spinal kyphosis, widespread affection of the epiphyses and normal intelligence. The authors experienced a case of Morquio's syndrome with typical clinical and radiological findings. The patient underwent bilateral supracondylar varus osteotomies for severe genu valgum deformities.
Congenital Abnormalities ; Dwarfism ; Epiphyses ; Genu Valgum ; Humans ; Intelligence ; Kyphosis ; Mucopolysaccharidosis IV ; Osteotomy ; Rare Diseases

PURPOSE: The mucopolysaccharidoses (MPSs) are a heterogeneous group of lysosomal storage disorders. They are caused by a deficiency of the enzymes involved in the degradation of glycosaminoglycans. Early recognition is important because recombinant enzyme replacement therapy is now available for MPS. We studied the clinical characteristics of 80 MPS children with the object of determining the epidemiological, clinical and radiological features in Korean MPS children. METHODS: Diagnosis of MPS was confirmed by skin fibroblast enzyme analysis in 80 patients between February 1995 and December 2004. Charts were retrospectively reviewed for clinical and radiological findings, as well as for intelligence and speech evaluations. RESULTS: Hunter syndrome (MPS type II) was the most prevalent type, appearing in 51/80 cases (64 %), followed by Sanfilippo syndrome (MPS III-18%), Hurler syndrome (MPS I-15%), and Morquio syndrome (MPS IV-4%). The average age at diagnosis was 5.5 years (range 1 to 20), and the male-to-female ratio was 4.7: 1. Typical radiographic changes were observed in 45/54 cases (83%). Mitral regurgitation was the most common cardiac defect. Moderate to profound mental retardation and hearing loss were present in 14/35 cases (56%) and 33/38 cases (82%), respectively. Four MPS II patients had bone marrow transplantation, with mixed outcomes. Five MPS I patients are currently on enzyme replacement therapy. CONCLUSION: Our study showed a high proportion of MPS II cases (64%), which may represent population variability. By studying the clinical features of these patients, we hope to alert pediatricians of the warning signs of MPS.
Bone Marrow Transplantation ; Child ; Diagnosis ; Enzyme Replacement Therapy ; Fibroblasts ; Glycosaminoglycans ; Hearing Loss ; Hope ; Humans ; Incidence ; Intellectual Disability ; Intelligence ; Korea ; Mitral Valve Insufficiency ; Mucopolysaccharidoses* ; Mucopolysaccharidosis I ; Mucopolysaccharidosis II ; Mucopolysaccharidosis III ; Mucopolysaccharidosis IV ; Retrospective Studies ; Skin

OBJECTIVETo detect potential mutation of galactosamine-6-sulfate (GALNS) gene in a Chinese girl affected with mucopolysaccharidosis type IV A (Morquio A syndrome).

METHODSThe patient was diagnosed by assaying the activities of mucopolysaccharidosis-related enzymes in leukocytes. Potential mutation in the GALNS gene was detected with PCR and Sanger sequencing.

RESULTSThe patient was characterized by short stature, skeletal deformities, normal intelligence, and auditory dysfunction. The activities of GALNS enzymes were low. A compound heterozygous missense mutation, c.1094G>T (p.Gly365Val)/c.938C>T (p.Thr313Met), was detected in the GALNS gene. The mutations were respectively inherited from her father and mother. Among them, the c.1094G>T (p.Gly365Val) mutation was not reported previously.

CONCLUSIONThe mutations c.1094G>T (p.Gly365Val)/c.938C>T (p.Thr313Met) probably underlie the pathogenesis of the disease in our patient.

Adult ; Base Sequence ; Child ; Child, Preschool ; Chondroitinsulfatases ; genetics ; Female ; Humans ; Male ; Molecular Sequence Data ; Mucopolysaccharidosis IV ; enzymology ; genetics ; Point Mutation

Objective: To analyze the clinical characteristics of patients with Mucopolysaccharidosis ⅣA (MPS ⅣA). Methods: A retrospective study was conducted on 111 patients with MPS ⅣA in Xinhua Hospital of Shanghai Jiao Tong University School of Medcine from December 2008 to August 2020, confirmed by enzyme activity and genetic testing. General situation, clinical manifestations and enzyme activity test results were analyzed. According to the clinical manifestations, it can be divided into severe, intermediate and mild group. The independent sample t test was used to compare the birth body length and weight of children with that of normal boys and girls, and group comparisons of enzyme activities were evaluated by median test. Results: One hundred and eleven unrelated patients, 69 males and 42 females, were classified into 3 subtypes: severe (n=85), intermediate (n=14), and mild (n=12). The age at symptom onset were 1.6 (1.0, 3.0) years, and at diagnosis were 4.3 (2.8, 7.8) years. Skeletal manifestations were observed in all patients and consisted mainly of pectus carinatum (96/111, 86.5%), motor dysfunction (78/111, 70.3%), spinal deformity (71/111, 64.0%), growth retardation (64/111, 57.7%), joint laxity (63/111, 56.8%) and genu valgum (62/111, 55.9%). Eighty-eight patients (88/111, 79.3%) with MPS ⅣA were also along with non-skeletal manifestations, mainly including snoring (38/111, 34.2%), coarse faces (34/111, 30.6%), and visual impairment (26/111, 23.4%). The most common skeletal manifestation was pectus carinatum (79 cases), and non-skeletal manifestation was snoring (30 cases) and coarse faces (30 cases) in severe patients, pectus carinatum (13 cases) and snoring (5 cases) in intermediate type, motor dysfunction (11 cases) and snoring (3 cases) and visual impairment (3 cases) in mild patients. The height and weight of severe patients began to fall below -2 s at 2-<5 years and 5-<7 years, respectively. At the age of 10-<15 years, the standard deviation score of the height of severe patients reached (-6.2±1.6) s in males and (-6.4±1.2) s in females, and the score of weight got (-3.0±1.1) s in males and (-3.5±0.5) s in females. The height of intermediate patients began to fall below -2 s at the age of 7-<10 years, and the standard deviation score of height were -4.6 s and -3.6 s in 2 males, and -4.6 s and -3.8 s in 2 females at the age of 10-<15 years. The weight remained within -2 s in 72.0% (18/25) of intermediate patients compared to age-matched healthy children. In the mild patients with MPS ⅣA, the mean standard deviation score of height and weight was within -2 s. The enzyme activities of mild patients (2.02 (1.05, 8.20) nmol/(17 h·mg)) were both significantly higher than that of intermediate (0.57 (0.47, 0.94) nmol/(17 h·mg)) and severe (0.22 (0, 0.59) nmol/(17 h·mg)) patients (Z=9.91, 13.98, P=0.005, 0.001), and the enzyme activity of intermediate patients was significantly higher than that of severe patients (Z=8.56, P=0.010). Conclusions: The clinical manifestations of MPS ⅣA are charactered by pectus carinatum, motor function impairment, spinal deformity and growth retardation. The clinical characteristics, growth rate and enzyme activity differ among the 3 subtypes of MPS ⅣA.
Male ; Child ; Female ; Humans ; Adolescent ; Mucopolysaccharidosis IV ; Pectus Carinatum ; Retrospective Studies ; Snoring ; China ; Mucopolysaccharidoses ; Growth Disorders ; Vision Disorders

PURPOSE: Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is rare lysosomal storage disorder caused by N-acetylgalactosamine-6-sulfatase (GALNS) deficiency. Only a few MPS IVA cases have been reported in the Korean literature; there is a paucity of research about clinical or radiologic findings for this disorder. Therefore, we studied clinical findings, radiological features, and genetic data of Korean MPS IVA patients for determining factors that may allow early diagnosis and that may thus improve the patients' quality of life. METHODS: MPS IVA was confirmed via assay for enzymatic activity of leukocytes in 10 patients. The GALNS gene was analyzed. Patients' charts were retrospectively reviewed for obtaining clinical features and evaluated for radiological skeletal surveys, echocardiography, pulmonary function test, and ophthalmologic test results. RESULTS: Nine patients had severe clinical phenotype, and 1 had an intermediate phenotype, on the basis of clinical phenotype criteria. Radiologic findings indicated skeletal abnormalities in all patients, especially in the hips and extremities. Eight patients had an odontoid hypoplasia, and 1 showed mild atlantoaxial subluxation and cord myelopathy. Genetic analysis indicated 10 different GALNS mutations. Two mutations, c.451C>A and c.1000C>T, account for 37.5% (6/16) and 25% (4/16) of all mutations in this samples, respectively. CONCLUSION: An understanding of the clinical and radiological features involved in MPS IVA may allow early diagnosis of MPS IVA. Adequate evaluations and therapy in the early stages may improve the quality of life of patients suffering from skeletal abnormalities and may reduce life-threatening effects of atlantoaxial subluxation.
Early Diagnosis ; Echocardiography ; Extremities ; Hip ; Humans ; Leukocytes ; Mucopolysaccharidoses ; Mucopolysaccharidosis IV ; Phenotype ; Quality of Life ; Respiratory Function Tests ; Retrospective Studies ; Spinal Cord Diseases ; Stress, Psychological

OBJECTIVETo provide rapid and accurate prenatal genetic diagnosis for a fetus with high risk of Morquio A syndrome.

METHODSBased on ascertained etiology of the proband and genotypes of the parents, particular mutations of the GALNS gene were screened at 10th gestational week with amplification refractory mutation system (ARMS), denaturing high performance liquid chromatography (DHPLC), and direct DNA sequencing.

RESULTSDHPLC screening has identified abnormal double peaks in the PCR products of exons 1 and 10, whilst only a single peak was detected in normal controls. Amplification of ARMS specific primers derived a specific product for the fetus's gene, whilst no similar product was detected in normal controls. Sequencing of PCR products confirmed that exons 1 and 10 of the GALNS gene from the fetus contained a heterozygous paternal c.106-111 del (p.L36-L37 del) deletion and a heterozygous maternal c.1097 T>C (p.L366P) missense mutation, which resulted in a compound heterozygote status.

CONCLUSIONThe fetus was diagnosed with Morquio A syndrome and a genotype similar to the proband. Termination of the pregnancy was recommended. Combined ARMS, DHPLC and DNA sequencing are effective for rapid and accurate prenatal diagnosis for fetus with a high risk for Morquio A syndrome. Such methods are particularly suitable for early diagnosis when pathogenesis is clear. Furthermore, combined ARMS and DHPLC are suitable for rapid processing of large numbers of samples for the identification of new mutations.

Base Sequence ; Chondroitinsulfatases ; genetics ; Female ; Genetic Testing ; methods ; Humans ; Molecular Sequence Data ; Mucopolysaccharidosis IV ; genetics ; Pedigree ; Pregnancy ; Pregnancy Complications ; genetics ; Prenatal Diagnosis ; methods ; Risk Factors

OBJECTIVETo study the molecular genetic mechanism of mucopolysaccharidosis type IV A(MPS IV A), and reveal the relationship between the genotype and phenotype, and provide a basis for prenatal gene diagnosis in the future.

METHODSA preliminary diagnosis was made by qualitative detection of urinary glycosaminoglycans of the suspected MPS IV A proband. Then, mutation detection was performed on the proband and her family members with PCR and direct sequencing of the PCR products. After a novel c.1567T to G mutation was detected, Xsp I restriction enzyme digestion and amplification refractory mutation system (ARMS) fast specific identification were established to analyze the sequences of exon 14 in GALNS gene, including 110 randomly selected healthy controls, the proband and other pedigree members. At the same time, bioinformatic approaches for protein secondary, tertiary structure prediction were applied to identify the novel pathologic mutation.

RESULTSThe proband's urine GAGs test was a weak positive(± ), and a c.1567T to G heterozygous termination codon mutation in exon 14 and a c.374C to T heterozygous missense mutation in exon 4 were found. The proband was compound heterozygous of the two mutations, so was her younger sister. Her mother was a carrier with only a c.1567T to G heterozygous mutation in exon 14. Her father had a heterozygous mutation of c.374C to T in exon 4. After Xsp I restriction enzyme digestion, healthy controls had three bands including 28 bp, 120 bp and 399 bp, while the proband and her mother had four bands consisting of 28 bp, 120 bp, 148 bp and 399 bp. For amplification by ARMS specific primers, it was negative for the controls, while it was positive for the proband and the carrier. The results of protein secondary and tertiary structure prediction showed that the c.1567T to G mutation located in the stop codon, resulted in stop codon (TAG) changing to glutamic acid (GAG), with the peptide chain extending 92 amino acid residues, and secondary and tertiary protein structure change, which were not found in the controls. The result of enzyme assay showed that the activity of GALNS enzyme in the affected child was 8.3 nmol/17h/mg pr, which was obviously lower than the normal value (the normal range is 41.9-92.1 nmol/17h/mg pr).

CONCLUSIONThese results illustrate that the c.1567 T to G is a novel pathologic mutation, which is the main cause of the disease in this family.

Amino Acid Sequence ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Chondroitinsulfatases ; chemistry ; genetics ; metabolism ; Female ; Genotype ; Humans ; Infant ; Molecular Sequence Data ; Mucopolysaccharidosis IV ; enzymology ; genetics ; Mutation ; genetics ; Pedigree ; Protein Conformation ; Sequence Alignment