Metabolic Myopathies: Experience of a Reference Center of Inherited Metabolic Diseases.

INTRODUCTION: Metabolic myopathies (MM) are a heterogeneous group of genetic disorders affecting metabolic pathways involved in energy production during rest, exercise and physiologic stress (fever, fasting, …). Impairments in the pathways of glycolysis/ glycogenolysis, fatty acid transport/oxidation or in the mitochondrial respiratory chain present primarily with exercise intolerance, myalgias, weakness, cramps, or rhabdomyolysis. Depending on aetiology, the diagnosis can be made through neonatal screening, pre-symptomatic or in the set of clinical manifestations for which a high level of suspicion is important. METHODS: Retrospective descriptive study of the clinical, biochemical, and molecular features of patients with a confirmed diagnosis of MM followed by the multidisciplinary team of the Reference Center of Inherited Metabolic Diseases of Centro Hospitalar Universitário de Lisboa Central from 2009 to 2022. RESULTS: Twenty-three patients with MM were included: 9 (39%) glycogen storage diseases (7 McArdle and 2 Pompe), 7 (30%) fatty acid oxidation disorders (3 CPT2, 3 LCHAD and 1 MAD deficiencies), 6 (26%) mitochondrial disease with significant muscle involvement (2 Pearson, 1 Kearns Sayre, 1 VARS2, 1 SUCLA2 and 1 MT-TL1 deficiencies), and 1 myoadenylate deaminase deficiency. Ages varied from 15 months to 35 years. Eighteen (78%) patients were diagnosed by clinical symptoms, 3 by newborn screening (LCHAD) and 2 were asymptomatic (1 Pompe and 1 McArdle). Frequent symptoms were rhabdomyolysis triggered by illness or exercise 12 (52%), fatigue 11 (48%), exercise intolerance 10 (43%), and myalgia 9 (43%). Eight (35%) patients (LCHAD and mitochondrial) had multisystemic involvement. In 20 (87%) patients, the diagnosis was confirmed by biochemical and/or genetic analysis and 3 (McArdle) by muscle biopsy. CONCLUSION: MM are a heterogeneous set of disorders, but a careful history may guide the differential diagnosis among biochemical pathways and other etiologies. Nowadays, molecular testing has become a powerful tool for diagnosis confirmation, surpassing muscular biopsy in most cases. Accurate diagnosis is important to identify who may benefit from specific therapeutic options, such as enzyme replacement therapy, restricted diets, emergency regime and cofactors. All patients benefit from adequate lifestyle modifications, individualized exercise prescription, nutritional intervention, and genetic counselling.

Pediatric Kaposi's sarcoma associated with immune reconstitution inflammatory syndrome.

Immune reconstitution inflammatory syndrome (IRIS) represents paradoxical immune-mediated inflammation in response to an infecting pathogen, occurring after initiation of antiretroviral therapy (ART), concomitantly with immune system recovery. It has also been described in Kaposi's sarcoma (KS). We report a case of a 9-year-old Guinean girl, who developed Kaposi's sarcoma, following introduction of ART. KS associated with immune reconstitution inflammatory syndrome is rare, especially in children, but with the increased use of ART is becoming more prevalent.

Use of gabapentin in the treatment of chronic pain in an adolescent with sickle cell disease.

Vaso-occlusive crises are the most common manifestation of sickle cell disease (SCD) and the main cause of hospital admission in these patients. There is emerging evidence that vaso-occlusive pain has both nociceptive and neuropathic components. However, the treatment of SCD-related pain with neuropathic drugs has not yet been systematically studied, particularly in children. We describe a 14-year-old girl with SCD and multiple hospital admissions for pain management for severe acute vaso-occlusive pain episodes. The patient was evaluated by a multidisciplinary team of specialists which considered that the chronic, refractory pain she was experiencing for years was probably neuropathic in origin and it was decided to start oral gabapentin (300 mg/day). At 10 months follow-up, the patient reported remarkable improvement in her quality of life with a significant decrease in the number of hospital admissions (three admissions for acute vaso-occlusive pain episodes in 10 months versus the previously monthly recurrences).

DPG-plus syndrome: new report of a rare entity.

Pituitary gland duplication is a particularly rare finding. Different theories have been proposed to explain its pathogenesis, however, this phenomenon is not yet totally understood. Recently, duplication of the pituitary gland (DPG)-plus syndrome has been described, associating DPG with other blastogenic defects. We present the clinical and imaging findings of a newborn girl with DPG, associated with multiple other midline anomalies, including a nasopharyngeal teratoma, palate cleft deformity, bifid nasal bridge, tongue and uvula, hypoplasia of the basis pontis and corpus callosum, duplication of the basilar artery and hypothalamic hamartoma. We describe our patient's multidisciplinary team approach and emphasise the importance of reporting upcoming cases, in order to give more insight into the understanding of this complex entity.