Table 2 Description of the signs and symptoms, and the course of included LSD

FD

Main symptoms at onset: fatigue, pain, fever crisis, digestive discomfort, heat stroke, pain in the extremities, foam in the urine, etc

Early presence of symptoms in paediatric age

Shortened life expectancy and a significant loss of quality of life

FD progression in target organs such as heart or kidneys, such as kidney failure, cardiomyopathy, and cerebrovascular ischemic events (stroke) with irreversible consequences for the patient

GD

The most common sign is a swollen spleen, which can be followed by bone disease and brain involvement and other problems such as tiredness, bleeding, bruising, and lung disease

Pain due to bone or neuronal involvement is the most common reason for consultation

Thrombocytopenia and anemia

Degenerative disease that can progress to increased visceromegaly (hepatomegaly and splenomegaly), recurrent bone pain, and lung involvement

PD

Symptoms little visible at onset with low impact on quality of life initially

The first symptoms are: muscle weakness and difficulty walking, breathing problems and infections of the respiratory system and failure to gain weight and growth at the expected rate. HyperCKemias

Muscle weakness (which can make it very difficult to walk), and breathing problems, that will finally lead to the use of walking aids and mechanical ventilation

MPSI

In the first years of life, patients present visible musculoskeletal alterations of varying degree, as well as corneal opacity

Very disabling degenerative disease that affects children in its most serious forms

High impact on quality of life due to physical limitations and cardiovascular and respiratory complications