- Reasons of a syndrome of Blum
- Symptoms of a syndrome of Blum
- Treatment of a syndrome of Blum
The Blum's Syndrome (BS), (English Bloom syndrome), is also known as Blum-Torre-Makhacheka's syndrome is a rare autosomal and recessive chromosomal frustration which is characterized by the high frequency of gaps and reorganizations in chromosomes of the sick person. This syndrome was for the first time described by the dermatologist Dr. David Bloom in 1954.
Reasons of a syndrome of Blum:
Mutations in a gene of BLM which is compound DNA геликаз (helikaza), cause emergence of a syndrome of Blum. DNA of a gelikaza (helikaza) are enzymes which untwist a two-chain spiral of DNA. Process of "promotion" consists of a large number of processes, such as synthesis of copies of DNA, a RNA transcription, DNA repair, etc.
When the cell prepares for division, chromosomes are duplicated in such a way that each neogenic structure receives a full range of chromosomes. Process of doubling is called - DNA replication. The mistakes made at DNA replication can lead to a mutation. Protein of BLM plays an important role in maintenance of stability of DNA in the course of replication. The mutations of a gene of BLM connected with Blum's syndrome deactivate protein which is coded by a gene of BLM and is a part of DNA of a helikaza, or break process of an expression (formation of protein). In other words there is no expression of this gene. Absence of BLM of protein or its low activity leads to increase in quantity of mutations for this reason molecular mechanisms by means of which BLM maintains stability of chromosomes still remain a subject for many researches.
At persons, since SATURDAY a large number of exchanges between homologous chromosomes or sister chromatids (two molecules DNA which are formed in the course of DNA replication) as a result of which the quantity of mutations significantly increases takes place. Besides, on much more often (concerning the persons which do not have Blum's syndrome) there is a damage of chromosomes and their reorganization.
Today scientists work on what to establish (or to disprove) existence of a feedforward between molecular processes in which the gene of BLM and change of chromosomes participates. Besides, communication between molecular defects in cells of persons since SATURDAY, chromosome mutations which collect in somatic cells (all cells of a body, except sexual) and many clinical signs of a syndrome of Blum is also one of the directions of clinical trials.
Blum's syndrome is inherited on autosomal recessively type. That is, both parents have to be carriers in order that their child got sick. Disease carriers among Ashkenazi's Jews, preferential are natives of Eastern Europe, 1 person on is 100. If both parents are the SATURDAY carriers, then in 25% of cases, the child can be a patient.
Those members of families which can be carriers of a disease are recommended to request genetic consultation or to pass genetic test. For carriers parents which plan to give birth to the child it is necessary to carry out prenatal diagnosis by means of cytogenetic and molecular methods. It is also possible to carry out the molecular analysis of DNA for definition of existence of mutations.
Symptoms of a syndrome of Blum:
Persons, patients of the WB, usually not high growth, with a characteristic enanthesis, kotoryevoznikat almost right after the first influence of sunshine. These rashes, as a rule arise on cheeks (causing reddening) and have the form of a butterfly. But rash can arise not only on a face, but also on other parts of a body on which sunshine got (a back, hands, etc.).
Such signs as are characteristic:
- high pitched voice;
- peculiar features of the person - the long and narrow person, a mandible micrognatia, a big nose and ears, changes of a xanthopathy, including emergence hypo-and a hyper-nevus pigmentosus and birthmarks;
- a teleangiectasia (expanded blood vessels) which can be shown on skin it is preferential on an upper part of a breast and back;
- a moderate immunodeficiency which is characterized by deficit of some classes of immunoglobulins which as researchers consider, leads to a recurrence of pneumonia and infections of ears;
- the hypogonadism is the morbid condition caused by insufficient secretion of androgens that is an organism of men, cannot produce sperm, so, the males affected with this disease - are infertile. At women this disease is shown by the premature termination of periods (a premature menopause), i.e. they have the lowered ability to the birth of children. However, some women who are ill Blum's syndrome can have children.
The complications resulting from influence of a disease can include chronic pulmonary diseases, a diabetes mellitus, emergence of difficulties when training. Some persons, have a mental retardation. The most dangerous complication it is possible to call increase in probability of developing of tumoral diseases.
Treatment of a syndrome of Blum:
Symptomatic treatment: photoprotective sredtstvo, carotinoids, vitamin E, immunoproofreaders. As prevention of a disease it is recommended to avoid kinship marriages.