Haemoglobin disorders. Shortage of blood and failure to thrive

Red blood cells  (RBCs) transport oxygen to all body tissues. These cells survive only for 120 days and then need to be replenished. Erythropoiesis is the process of RBC production. In healthy individuals, erythropoiesis ensures all tissues are amply supplied with oxygen. In addition, blood loss due to injury leads to a drop in the physiological oxygen level that will cause erythropoiesis. Any defect in erythropoiesis leads to several physiological disorders, including thalassemia, anemia, and...

The first thing a clinician sees is the skin, so the examination of the skin should be part of any thorough physical examination. Most skin disorders are relatively benign, but a few, including melanomas, can be fatal if untreated. A couple of the more noticeable disorders, albinism and vitiligo, affect the appearance of the skin and its accessory organs.
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...

Red blood cells  (RBCs) transport oxygen to all body tissues. These cells survive only for 120 days and then need to be replenished. Erythropoiesis is the process of RBC production. In healthy individuals, erythropoiesis ensures all tissues are amply supplied with oxygen. In addition, blood loss due to injury leads to a drop in the physiological oxygen level that will cause erythropoiesis. Any defect in erythropoiesis leads to several physiological disorders, including thalassemia, anemia, and...

Disorders of erythrocytes, or red blood cells (RBCs), include a range of conditions affecting their number, shape, or function.
Erythrocyte disorders can be broadly categorized into two main types: anemic and polycythemic conditions.
A low oxygen-carrying capacity of the blood due to the loss, lower production, or destruction of erythrocytes is termed anemia. Hemorrhagic anemia, for example, occurs when bleeding from an external wound or internal ulcer reduces erythrocyte counts.
On the other...

Leukocyte disorders can lead to either leukopenia, characterized by an abnormally low leukocyte count, or leukocytosis, marked by a very high leukocyte number.
Leukopenia may result from bone marrow disorders, autoimmune diseases, and infectious diseases. For example, conditions such as multiple myeloma and aplastic anemia can impair the bone marrow's ability to produce adequate leukocytes. Similarly, autoimmune diseases like lupus and viral infections such as HIV can prompt the immune system...

Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...