Mucolipidosis II

A term male infant, born to a 20-year-old primigravida, was admitted for respiratory distress. prenatal ultrasound examination showed shortened long bones. The parents were orthodox Jews and there history of second-degree consanguinity. deceased paternal cousin diagnosed with mucolipidosis. Birthweight (2175 g), length, head circumference below the third percentile. On physical examination, infant had prominent forehead large fontanelle, low set ears, eyes, telecanthus, maxillary hypoplasia, gingival hyperplasia, narrow chest, distended abdomen, short limbs, bowing lower extremities, generalized hypotonia. Radiographs revealed bell-shaped small thoracic cavity, lung volumes bilateral rib fractures (Figure, C ), diffuse osteopenia and, subperiosteal bone destruction new formation, decreased size vertebral bodies A-G). Lysosomal enzyme hydrolase levels in plasma high, normal activity leukocytes. Urinary glycosaminoglycans oligosaccharides negative diagnosis mucolipidosis II confirmed on genetic testing. Mucolipidosis alpha/beta or inclusion cell disease is an autosomal-recessive lysosomal storage disorder caused by mutation gene GNPTAB (alpha beta subunits N-acetylglucosamine-1-phosphotransferase), which located chromosome 12q23.2. This alteration leads deficiency N-acetylglucosamine-1-phosphotransferase that normally transfers phosphate mannose residues. disrupts post-translational modification acid hydrolases increased extracellular secretion profound intracellular hydrolases, thereby leading accumulation substrates, usual pathology diseases. Because it characterized presence vacuole-like inclusions lymphocytes also called disease. In early infancy, radiographic features may resemble rickets hyperparathyroidism mineralization, periosteal “cloaking,” ossification delay, epiphyseal dysplasia, platyspondyly (butterfly anterior beaking) bodies, wide oar-shaped ribs, hypoplasia ilea shallow acetabular fossae, pelvic dysplasia. this progressive, later signs include sclerosis, stippling, joint restriction other multisystem effects such as severe neuropsychomotor developmental disorder. Potential management several disorders, including mucopolysaccharidosis, includes replacement therapy, enhancement therapeutics, substrate reduction molecule hematopoietic stem transplantation, clustered regularly interspaced palindromic repeats based genome editing. alpha/beta, treatment even when instituted first few months life, have not proven be beneficial. Some difficulties encountered are related inability edited cells editing machinery cross blood brain barrier treatment. Other reasons limited improvement after delivery active phosphotransferase transplantation could due number pathways affected. Studies ultrasound-mediated blood-brain disruption, penetrating peptides, nanoparticle systems ongoing. At present, supportive.