Cystic fibrosis is an autosomal recessive disease caused by structure abnormalities in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. It is characterized by severe course and poor prognosis without or with insufficient treatment. Approval of pathogenetic therapy medications, CFTR modulators (potentiators and correctors), for clinical use in 2012 in the United States has reduced mortality from this disease. This article provides the overview of studies on clinical efficacy and safety of ivacaftor/lumacaftor combination (Iva/Lum) — the first licensed CFTR modulator medication for homozygous patients with F508del variant. It was shown that Iva/Lum increases lung function, reduce the number of acute conditions of bronchopulmonary process (including those that require antibiotics and hospitalization), partially restores pancreas exocrine function, increases body weight and mass growth index, and improves quality of life. It allows considering it as favorable effect on the course and prognosis of cystic fibrosis. It was also noted that the early onset of the drug administration (from the age of two) positively affects the prognosis of the disease, increasing life expectancy and improving quality of life.

Background. Mucopolysaccharidosis type I is disease from the group of lysosomal storage disease developing due to mutations in the IDUA gene. It leads to the accumulation of glycosaminoglycans (GAGs) in organs and tissues. Joints damage in this disease is systemic and progressive.

Objective. The aim of the study. Nowadays, relevant issue is to investigate the effects of various types of pathogenetic therapy on the state of the osteoarticular system in patients with severe and mild phenotypes of MPS I to prevent further progression of joint pathology.

Methods. The study included 46 patients diagnosed with “mucopolysaccharidosis type I”. 35 children had severe phenotype (Hurler syndrome) and 11 — with mild phenotypes (Hurler-Scheie and Scheie syndromes). The onset age of clinical manifestations in osteoarticular system, the state of large and small joints, and the presence of cervical stenosis according to the therapy were evaluated in these patients.

Results. The osteoarticular system pathology can be usually revealed in all patients with MPS I, in both mild and severe phenotypes. The contractures of shoulder, ulnar, wrist, and small hand joints have been revealed in most patients with Hurler syndrome, regardless of the administered therapy. Hip joints pathology was observed in children who was administered with: enzyme replacement therapy (ERT) — in 46.7% of cases, hematopoietic stem cell transplantation (HSCT) in combination with ERT — in 34.4% of cases. Patients with Hurler syndrome administered with HSCT in combination with ERT had cervical stenosis statistically significantly more rarely (p = 0.018) compared to patients treated with ERT only. Patients with Hurler syndrome who were on ERT had statistically significantly lower growth rates than patients after HSCT in combination with ERT. Lesions in ulnar, wrist, knee and small hand joints were the most common in children with mild phenotypes (in 90% of cases).

Conclusion. Combined therapy (HSCT and ERT) in patients with Hurler syndrome reduces severe manifestations in osteoarticular system, including children with a pathogenic nucleotide variant c.208C>T in a homozygous state.

Background. Spinal muscular atrophy 5q (5q SMA) is the most frequent autosomal recessive hereditary neuromuscular disease. Molecular genetic testing is used for SMA diagnosis, and it can confirm only 5q SMA. The clinical findings and results of paraclinical studies may overlap with hereditary primary-muscular diseases making the diagnosis difficult and delaying the administration of pathogenetic treatment for 5q SMA.

Clinical case description. Clinical description of 10 patients with 5q SMA aged from 3 months to 25 years with different severity of proximal tetraparesis, skeletal muscular atrophy and tendon reflexes depression is given. 3 patients under 2 years of age with myogenic pattern at needle electromyography (nEMG) in lateral vastus muscle and 7 patients over 2 years of age with increased levels of creatine phosphokinase (CPK) in blood serum were mistakenly diagnosed for inherited primary-muscular diseases for the period from 1 month to 12 years. After the genetic counselling based on the disease course and clinical findings we suspected and later confirmed 5q SMA.

Conclusion. In case of flaccid proximal tetraparesis associated with myogenic pattern at nEMG in young children or with increased CPK levels at late manifestation it is crucial to perform differential diagnosis of 5q SMA since there are options of pathogenetic therapy. 

Background. The use of hypercaloric formulas in cystic fibrosis patients has the risks of negative effects on carbohydrate and lipid metabolism. Thus, it is interesting to analyze the efficacy of malnutrition correction and the safety of hypercaloric enteral products with a low glycemic index and with medium-chain triglycerides content of 50%.

Objective. The aim of the study is analyze the efficacy of malnutrition correction with therapeutic hypercaloric product for enteral nutrition in children with cystic fibrosis.

Methods. The study included patients aged from 3 to 18 years with malnutrition (BMI < 50 percentile) who were prescribed therapeutic hypercaloric formula to correct the malnutrition. Anthropometric indicators (height, body weight), actual nutritional status, pancreatin doses, lung function, carbohydrate metabolism rates, and cholestasis marker (bile acid concentration) were measured initially and after 1 month of using formula nutrition.

Results. The children’ body weight (Me) has increased from 24.5 (21.2; 38.7) to 25.3 kg (21.6; 39.7) (p = 0.001), growth (Me) — from 133.5 (120.2; 146.5) to 136.5 cm (123.0; 148.5) (p < 0.001) after 1 month of using hypercaloric formula. The growth percentile increased from 33 to 40, the z-criterion values — from –0.5 to –0.3 SD (p < 0.001). There was no increase in BMI in dynamics due to the fact that the growth of children was ahead of body weight increase. The daily energy intake increased by an average of 450 kcal that was 21.8% regarding physiological need.

Conclusion. The inclusion of hypercaloric formula in the diet of children with cystic fibrosis for 1 month significantly increases the indicators of linear growth and positively affects the overall physical development. There were no negative effect of formula on carbohydrate and lipid metabolism.

Background. The efficacy and safety of onasemnogene abeparvovec have been demonstrated in patients with spinal muscular atrophy (SMA) in several clinical and observational studies. Gene replacement therapy results in Russian patients with SMA is not investigated yet.

Objective. The aim of the study is to study the safety and efficacy of onasemnogene abeparvovec in children with SMA in real clinical practice.

Methods. The study included patients with proximal 5q SMA administered with onasemnogene abeparvovec. Diagnosis was verified by biallelic deletion in the 7th exon of the SMN1 gene. Gene replacement therapy was administered according to the decision of neurologists consensus in case of the absence of antibodies to the adeno-associated serotype 9 virus. The therapy safety was estimated via clinical and laboratory data from the hospital (at least 7 days) and from outpatient departments (at least 60 days). Efficacy was estimated via CHOP INTEND scale and mastering new motor skills ≥ 6 months after therapy onset.

Results. Treatment outcomes were studied in 10 SMA patients aged 19 months (15; 21). All patients developed at least one clinical manifestation (hyperthermia, vomiting, lethargy and/or loose stool) associated with drug administration during the first week of follow-up. Increased hepatic transaminases activity and monocytosis was recorded in all patients, thrombocytopenia — in 9, neutropenia — in 5, increased troponin I concentration — in 3. In three cases it was necessary to increase the oral prednisolone dose of to 2 mg/kg, in one case — the dexamethasone pulse therapy dose. The therapy efficacy was monitored ≥ 6 months after therapy onset via the CHOP INTEND scale in 2 patients (scores increased by 32 and 19 points, respectively), and via mastering new motor skills in 8 patients (positive dynamics was noted in 7 cases).

Conclusion. The onasemnogene abeparvovec is relatively safe and quite effective for using in real clinical practice

Background. Hermansky–Pudlak syndrome type 6 is rare hereditary disease caused by pathogenic variants in base sequence, deletions, and insertions in the HPS6 gene encoding the transmembrane protein of the same name. This disease occurs with hemorrhagic syndrome, oculocutaneous albinism, and inflammatory bowel diseases (in some cases). The clinical picture of the disease, including the gastrointestinal tract pathology, has not been studied completely due to the syndrome rarity.

Clinical case description. We would like to present the description of clinical case of the patient with Hermansky–Pudlak syndrome type 6 accompanied with bowel vascular malformation. The patient diagnosed with “oculocutaneous albinism” at the age of 4.5 has shown recurrent intestinal bleedings, blood hemoglobin concentration decrease to 45 g/l; platelet count, mean platelet volume and platelet distribution width remained within the reference values. Slight decrease of Quick’s value to 68% (normal range 70–120%) was revealed. The study of platelet morphology has revealed a decrease in the number of dense granules: < 3 in 25% platelets, < 6 — in 64%. Ultrasound investigation has revealed signs of vascular malformation in ascending colon: significant changes of diameter (widening) and shape of intestinal wall vessels. Molecular genetic analysis (NGS) has revealed the nucleotide variant c.1133T>G (p.Leu378Arg) in homozygous state in the HPS6 gene. The same variant in homozygous state was revealed in the younger proband sister who also had vascular changes in the ascending colon wall.

Conclusion. Differential diagnosis of Germanic–Pudlak syndrome type 6 should be performed with other types of this syndrome as well as with syndrome and non-syndrome forms of oculocutaneous albinism. Molecular genetic confirmation of the diagnosis is suggested via massive parallel sequencing (NGS) methods (exome sequencing included) due to the rarity of Hermansky–Pudlak syndrome.

Background. Mucopolysaccharidosis type VI (MPS VI, Maroteaux–Lamy syndrome) is rare autosomal-recessive multisystem disease, one of the group of lysosomal storage diseases. The MPS VI pathogenesis is determined by arylsulfatase B enzyme deficiency caused by mutations in the ARSB gene. There are only few published clinical examples of this disease that covers the results of early enzyme replacement therapy (ERT) onset.

Clinical case description. The child was suspected to have lysosomal storage disease at the age of 1.5 months, it was based on microscopic analysis of blood smears: Alder abnormality was revealed (granulations and red-violet inclusions in neutrophils, monocytes, lymphocytes cytoplasm). The diagnosis was confirmed at the age of 3 months: increased glycosaminoglycans (GAGs) concentration in the urine, arylsulfatase B activity decrease in dried blood spots, and pathogenic variant c.943C>T (p. R315X) in the ARSB gene in homozygous state were revealed. ERT with galsulfase was started at the age of 7 months. There was decrease in excretion of GAGs in urine to normal level after 9 and 15 months of therapy. Normal growth and body proportions for the patient’s age were determined 3 years after continuous ERT. However, there was progression of multiple dysostosis and joint stiffness, as well as eyes lesion.

Conclusion. Early ERT onset cannot completely stop MPS VI progression but it allows to reduce the severity of several symptoms and improves patient’s quality of life.

Xeroderma pigmentosum is rare genetic disorder characterized by increased skin sensitivity to damaging ultraviolet (UV) light. First symptoms manifest at early age in most cases (up to 75%). Chronic damage due to sun exposure is common, it has different stages of changes and risk of further development of malignant tumors that depends on the gene involved. Additionally to skin manifestations there are various neurological disorders such as progressive cognitive dysfunctions, sensorineural hearing loss, ataxia, pyramid and extrapyramidal disorders, areflexia. Treatment of patients with xeroderma pigmentosum is mostly symptomatic and preventive (protection against UV). Nowadays targeted medications for DNA repair and increasing cells resistance to UV light, thus preventing the oncological diseases, are under development.

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is X-linked hereditary disease from the group of lysosomal storage disease. Its prevalence is 3–7 cases per 1 million live-born boys. MPS II occurs due to the deficiency of iduronate-2-sulfatase enzyme because of pathological changes in the structure of the IDS gene. Enzyme deficiency leads to the accumulation of glycosaminoglycans (GAGs), dermatan sulfate and heparan sulfate, in lysosomes. This leads to the damage of various organs and systems in the body with further development of clinical picture of the disease: coarse face, recurrent infections of upper respiratory tract, hearing loss up to deafness, cardiovascular and respiratory systems pathologies, hepatosplenomegaly, musculoskeletal system abnormalities, low growth, central nervous system damage. Enzyme replacement therapy with idursulfase, that was introduced in clinical practice 15 years ago, has significantly changed the quality of life of these patients. Idursulfase is purified form of natural lysosomal enzyme iduronate-2-sulfatase obtained via human cell line. Exogenous enzyme entry promotes GAGs catabolism in cells. This article provides outcomes analysis of foreign and Russian studies on the efficacy and safety of this medication, and its effect on MPS II patients survivability.

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is rare hereditary disease caused by changes in the IDS gene and associated deficiency of lysosomal enzyme iduronate-2-sulfatase (I2S). The main treatment scheme for children with MPS II is enzyme replacement therapy (ERT) with recombinant human I2S. The major issue of ERT is development of allergic (sometimes up to severe anaphylaxis) reactions to recombinant enzymes. The article covers features of infusion-related reactions to ERT, it describes pathogenesis, diagnostic criteria management algorithm of anaphylaxis. Whereas, there is the need of further studies on allergic infusion-related reactions to ERT in children.