Retrospective evaluation of clinical, laboratory and molecular genetic features of lysosomal storage diseases

In this study, the clinical, laboratory and molecular genetic characteristics of the patients followed up with the diagnosis of lysosomal storage disease (LSD) were examined retrospectively, compared with the literature and the treatment responses of patients with mucopolysaccharidosis and Pompe disease who received enzyme replacement therapy were evaluated. A total of 480 patients who were followed up with the diagnosis and pre-diagnosis of LSD between 1980 and 2020 were included in the study. 76.9% of the patients had mucopolysaccharidosis, 7.3% mucolipidosis, 7.1% sphingolipidosis, 5% Pompe disease, 1.3% oligosaccharidosis, 1% cystinosis, 0.83% were followed up with the diagnosis of multiple sulfatase deficiency and 0.63% lipid storage diseases. The gender distribution of the patients was 60.4% male and 39.6% female. Age at diagnosis ranged from 0 to 55 years, with a median of 2.2 years and a mean of 4.4±7.3 years. There was consanguinity in 77.4% of the patients and a family history of similar or another metabolic disease in 40.7% of the patients. The patients were admitted to the hospital most frequently due to developmental delay (30.8%), orthopedic problems (23.7%) and family history of metabolic disease (10.3%). In the clinical and laboratory evaluations of the patients, coarse facial appearance (81.2%), developmental delay/mental disability (63.4%), valvular valve disease (58.5%), hearing loss (52.5%), corneal opacities (%) 41.7%), craniocervical junction stenosis (39.8%), recurrent lung infections (36%), hepatomegaly/splenomegaly (33.5%), thoracolumbar kyphosis (28.5%) were the most common findings. When the final situation was evaluated, 60% of the patients died. When all system findings of MPS patients were compared for age at treatment and treatment responses, there was a statistically significant difference between early age at treatment and good treatment response for respiratory system findings (p=0.035). There was no statistically significant difference in walking test averages before and after treatment (p=0.185). Although improvement in osteoarticular findings was reported in MPS patients who received enzyme therapy, worsening stature and cardiac findings were observed. No statistically significant results were found when osteoarticular, cardiovascular, neurological, and respiratory system findings were compared with the age at treatment and treatment duration in Pompe patients. Muscle and cardiac findings improved in Pompe patients who received enzyme therapy. In conclusion, early diagnosis and early initiation of enzyme replacement therapy may positively affect respiratory system findings and annual height growth rates in MPS patients and muscle and cardiac findings in infantile Pompe patients.