Malignant infantile osteopetrosis | |
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Other names | Infantile autosomal recessive osteopetrosis, Infantile osteopetrosis |
Child with osteopetrosis |
Malignant infantile osteopetrosis is a rare osteosclerosing type of skeletal dysplasia that typically presents in infancy and is characterized by a unique radiographic appearance of generalized hyperostosis (excessive growth of bone).
The generalized increase in bone density has a special predilection to involve the medullary portion with relative sparing of the cortices. [1] Obliteration of bone marrow spaces and subsequent depression of the cellular function can result in serious hematologic complications. Optic atrophy and cranial nerve damage secondary to bony expansion can result in marked morbidity. The prognosis is extremely poor in untreated cases. [2] Plain radiography provides the key information to the diagnosis. Clinical and radiologic correlations are also fundamental to the diagnostic process, with additional gene testing being confirmatory.
Hematologic manifestations related to bone marrow suppression and subsequent pancytopenia are a major source of morbidity and mortality. Additionally, extramedullary hematopoiesis can result in liver and spleen dysfunction. Cranial nerve dysfunction and neurologic complications are usually associated with infantile osteopetrosis. Expansion of the skull bone leads to macrocephaly. Additionally, linear growth retardation that is not apparent at birth, delayed motor milestones and poor dentition can occur. [2]
The generalized increase in bone density of the medullary portion predominates with relative sparing of the cortices. The axial and appendicular skeleton are uniformly involved. Malignant infantile osteopetrosis is known for exhibiting specific plain radiographic abnormalities: [1]
The differential diagnosis of malignant infantile osteopetrosis includes other genetic skeletal dysplasias that cause osteosclerosis. They are collectively known as osteosclerosing dysplasias. The differential diagnosis of genetic osteosclerosing dysplasias including infantile osteopetrosis has been tabulated [1] and illustrated in literature citations. [3]
The only effective line of treatment for malignant infantile osteopetrosis is hematopoietic stem cell transplantation. [2] [4] [5] It has been shown to provide long-term disease-free periods for a significant percentage of those treated. [2] It can impact both hematologic and skeletal abnormalities; [2] [4] and has been used successfully to reverse the associated skeletal abnormalities. [4] [5]
Radiographs of at least one case with malignant infantile osteopetrosis have demonstrated bone remodeling and recanalization of medullar canals following hematopoietic stem cell transplantation. This favorable radiographic response could be expected within one year following the procedure [4] [5] – nevertheless, primary graft failure can prove fatal. [2]
A myelodysplastic syndrome (MDS) is one of a group of cancers in which immature blood cells in the bone marrow do not mature, and as a result, do not develop into healthy blood cells. Early on, no symptoms typically are seen. Later, symptoms may include fatigue, shortness of breath, bleeding disorders, anemia, or frequent infections. Some types may develop into acute myeloid leukemia.
Bone marrow is a semi-solid tissue found within the spongy portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production. It is composed of hematopoietic cells, marrow adipose tissue, and supportive stromal cells. In adult humans, bone marrow is primarily located in the ribs, vertebrae, sternum, and bones of the pelvis. Bone marrow comprises approximately 5% of total body mass in healthy adult humans, such that a man weighing 73 kg (161 lbs) will have around 3.7 kg (8 lbs) of bone marrow.
Fanconi anaemia (FA) is a rare, AR, genetic disease resulting in impaired response to DNA damage in the FA/BRCA pathway. Although it is a very rare disorder, study of this and other bone marrow failure syndromes has improved scientific understanding of the mechanisms of normal bone marrow function and development of cancer. Among those affected, the majority develop cancer, most often acute myelogenous leukemia (AML), MDS, and liver tumors. 90% develop aplastic anemia by age 40. About 60–75% have congenital defects, commonly short stature, abnormalities of the skin, arms, head, eyes, kidneys, and ears, and developmental disabilities. Around 75% have some form of endocrine problem, with varying degrees of severity. 60% of FA is FANC-A, 16q24.3, which has later onset bone marrow failure.
Osteosclerosis is a disorder that is characterized by abnormal hardening of bone and an elevation in bone density. It may predominantly affect the medullary portion and/or cortex of bone. Plain radiographs are a valuable tool for detecting and classifying osteosclerotic disorders. It can manifest in localized or generalized osteosclerosis. Localized osteosclerosis can be caused by Legg–Calvé–Perthes disease, sickle-cell disease and osteoarthritis among others. Osteosclerosis can be classified in accordance with the causative factor into acquired and hereditary.
Osteopetrosis, literally "stone bone", also known as marble bone disease or Albers-Schönberg disease, is an extremely rare inherited disorder whereby the bones harden, becoming denser, in contrast to more prevalent conditions like osteoporosis, in which the bones become less dense and more brittle, or osteomalacia, in which the bones soften. Osteopetrosis can cause bones to dissolve and break.
Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood in order to replicate inside of a patient and to produce additional normal blood cells. It may be autologous, allogeneic or syngeneic.
Hematopoietic stem cells (HSCs) are the stem cells that give rise to other blood cells. This process is called haematopoiesis. In vertebrates, the very first definitive HSCs arise from the ventral endothelial wall of the embryonic aorta within the (midgestational) aorta-gonad-mesonephros region, through a process known as endothelial-to-hematopoietic transition. In adults, haematopoiesis occurs in the red bone marrow, in the core of most bones. The red bone marrow is derived from the layer of the embryo called the mesoderm.
Intramembranous ossification is one of the two essential processes during fetal development of the gnathostome skeletal system by which rudimentary bone tissue is created. Intramembranous ossification is also an essential process during the natural healing of bone fractures and the rudimentary formation of bones of the head.
Hypophosphatasia (; also called deficiency of alkaline phosphatase, phosphoethanolaminuria, or Rathbun's syndrome; sometimes abbreviated HPP) is a rare, and sometimes fatal, inherited metabolic bone disease. Clinical symptoms are heterogeneous, ranging from the rapidly fatal, perinatal variant, with profound skeletal hypomineralization, respiratory compromise or vitamin B6 dependent seizures to a milder, progressive osteomalacia later in life. Tissue non-specific alkaline phosphatase (TNSALP) deficiency in osteoblasts and chondrocytes impairs bone mineralization, leading to rickets or osteomalacia. The pathognomonic finding is subnormal serum activity of the TNSALP enzyme, which is caused by one of 388 genetic mutations identified to date, in the gene encoding TNSALP. Genetic inheritance is autosomal recessive for the perinatal and infantile forms but either autosomal recessive or autosomal dominant in the milder forms.
Extramedullary hematopoiesis refers to hematopoiesis occurring outside of the medulla of the bone. It can be physiologic or pathologic.
Osteochondrodysplasia is a general term for a disorder of the development (dysplasia) of bone ("osteo") and cartilage ("chondro"). Osteochondrodysplasias are rare diseases. About 1 in 5,000 babies are born with some type of skeletal dysplasia. Nonetheless, if taken collectively, genetic skeletal dysplasias or osteochondrodysplasias comprise a recognizable group of genetically determined disorders with generalized skeletal affection. Osteochondrodysplasias can result in marked functional limitation and even mortality.
Pseudoachondroplasia is an inherited disorder of bone growth. It is a genetic autosomal dominant disorder. It is generally not discovered until 2–3 years of age, since growth is normal at first. Pseudoachondroplasia is usually first detected by a drop of linear growth in contrast to peers, a waddling gait or arising lower limb deformities.
Treosulfan, sold under the brand name Trecondi, is a medication given to people before they have a bone marrow transplant from a donor known as allogeneic hematopoietic stem cell transplantation. It is used as a 'conditioning' treatment to clear the bone marrow and make room for the transplanted bone marrow cells, which can then produce healthy blood cells. It is used together with another medicine called fludarabine in adults and children from one month of age with blood cancers as well as in adults with other severe disorders requiring a bone marrow transplant.
Boomerang dysplasia is a lethal form of osteochondrodysplasia known for a characteristic congenital feature in which bones of the arms and legs are malformed into the shape of a boomerang. Death usually occurs in early infancy due to complications arising from overwhelming systemic bone malformations.
The haematopoietic system is the system in the body involved in the creation of the cells of blood.
Guo Mei is a hematologist and associate director of 307th Hospital of Chinese People’s Liberation Army and deputy director of Radiation Research Institute.
The Emberger syndrome is a rare, autosomal dominant, genetic disorder caused by familial or sporadic inactivating mutations in one of the two parental GATA2 genes. The mutation results in a haploinsufficiency in the levels of the gene's product, the GATA2 transcription factor. This transcription factor is critical for the embryonic development, maintenance, and functionality of blood-forming, lympathic-forming, and other tissues. The syndrome includes as its primary symptoms: serious abnormalities of the blood such as the myelodysplastic syndrome and acute myeloid leukemia; lymphedema of the lower limbs, and sensorineural hearing loss. However, the anomalies caused by GATA2 mutations are highly variable with some individuals showing little or no such symptoms even in old age while others exhibit non-malignant types of hematological anomalies; lymphedema in areas besides the lower limbs, little or no hearing loss; or anomalies in other tissues. The syndrome may present with relatively benign signs and/or symptoms and then progress rapidly or slowly to the myelodysplastic syndrome and/or acute myeloid leukemia. Alternatively, it may present with one of the latter two life-threatening disorders.
Shimon Slavin, is an Israeli professor of medicine. Slavin pioneered the use of immunotherapy mediated by allogeneic donor lymphocytes and innovative methods for stem cell transplantation for the cure of hematological malignancies and solid tumors, and using hematopoietic stem cells for induction of transplantation tolerance to bone marrow and donor allografts.
Dysosteosclerosis (DSS), also known as autosomal recessive dysosteosclerosis or X-linked recessive dysosteosclerosis, is a rare osteoclast-poor form of osteosclerosis that is presented during infancy and early childhood, characterized by progressive osteosclerosis and platyspondyly. Platyspondyly and other skeletal abnormalities are radiographic features of the disease which distinguish DSS from other osteosclerotic disorders. Patients usually experience neurological and psychological deterioration, therefore patients are commonly associated with delayed milestones.