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Baller–Gerold Syndrome
Baller–Gerold syndrome (BGS) is a rare genetic syndrome that involves premature fusion of the skull bones and malformations of facial, forearm and hand bones. The symptoms of Baller–Gerold syndrome overlap with features of a few other genetics disorders: Rothmund–Thomson syndrome and RAPADILINO syndrome. The prevalence of BGS is unknown, as there have only been a few reported cases, but it is estimated to be less than 1 in a million. The name of the syndrome comes from the researchers Baller and Gerold who discovered the first three cases. Signs and symptoms The most common and defining features of BGS are craniosynostosis and radial ray deficiency. The observations of these features allow for a diagnosis of BGS to be made, as these symptoms characterize the syndrome. Craniosynostosis involves the pre-mature fusion of bones in the skull. The coronal craniosynostosis that is commonly seen in patients with BGS results in the fusion of the skull along the coronal suture. Bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rothmund–Thomson Syndrome
Rothmund–Thomson syndrome (RTS) is a rare autosomal recessive skin condition. There have been several reported cases associated with osteosarcoma. A hereditary basis, mutations in the DNA helicase ''RECQL4'' gene, causing problems during initiation of DNA replication has been implicated in the syndrome. Signs and symptoms * Sun-sensitive rash with prominent poikiloderma and telangiectasias * Juvenile cataracts * Saddle nose * Congenital bone defects, including short stature and radial ray anomalies such as absent thumbs * Hair growth problems (absent eyelashes, eyebrows and/or hair) * Hypogonadism has not been well documented * Hypodontia * Calcium problems (not documented in journals) * Ear problems (not documented in journals but identified by patients in support groups) * Produces osteosarcoma The skin is normal at birth. Between 3 and 6 months of age, the affected carrier develops poikiloderma on the cheeks. This characteristic "rash" that all RTS carriers have can develop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, excessive amount of apoptosis of cells, and disuse or lack of exercise or disease intrinsic to the tissue itself. In medical practice, hormonal and nerve inputs that maintain an organ or body part are said to have ''trophic'' effects. A diminished muscular trophic condition is designated as ''atrophy''. Atrophy is reduction in size of cell, organ or tissue, after attaining its normal mature growth. In contrast, hypoplasia is the reduction in the cellular numbers of an organ, or tissue that has not attained normal maturity. Atrophy is the general physiological process of reabsorption and breakdown of tissues, involving apoptosis. When it occurs as a result of disease or loss of trophic support because of other diseases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Counseling
Genetic counseling is the process of investigating individuals and families affected by or at risk of genetic disorders to help them understand and adapt to the medical, psychological and familial implications of genetic contributions to disease; this field is considered necessary for the implementation of genomic medicine. The process integrates: * Interpretation of family and medical histories to assess the chance of disease occurrence or recurrence * Education about inheritance, testing, management, prevention, resources * Counseling to promote informed choices, adaptation to the risk or condition and support in reaching out to relatives that are also at risk History The practice of advising people about inherited traits began around the turn of the 20th century, shortly after William Bateson suggested that the new medical and biological study of heredity be called "genetics". Heredity became intertwined with social reforms when the field of modern eugenics took form. Althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allele
An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chromosomal or genomic location of a gene or any other genetic element is called a locus (plural: loci) and alternative DNA sequences at a locus are called alleles." The simplest alleles are single nucleotide polymorphisms (SNP). but they can also be insertions and deletions of up to several thousand base pairs. Popular definitions of 'allele' typically refer only to different alleles within genes. For example, the ABO blood grouping is controlled by the ABO gene, which has six common alleles (variants). In population genetics, nearly every living human's phenotype for the ABO gene is some combination of just these six alleles. Most alleles observed result in little or no change in the function of the gene product it codes for. However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dominance (genetics)
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes ( autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance such as incomplete d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicases
Helicases are a class of enzymes thought to be vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two hybridized nucleic acid strands (hence '' helic- + -ase''), using energy from ATP hydrolysis. There are many helicases, representing the great variety of processes in which strand separation must be catalyzed. Approximately 1% of eukaryotic genes code for helicases. The human genome codes for 95 non-redundant helicases: 64 RNA helicases and 31 DNA helicases. Many cellular processes, such as DNA replication, transcription, translation, recombination, DNA repair, and ribosome biogenesis involve the separation of nucleic acid strands that necessitates the use of helicases. Some specialized helicases are also involved in sensing of viral nucleic acids during infection and fulfill a immunological function. Function Helicases are oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Helicase
Helicases are a class of enzymes thought to be vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two hybridized nucleic acid strands (hence '' helic- + -ase''), using energy from ATP hydrolysis. There are many helicases, representing the great variety of processes in which strand separation must be catalyzed. Approximately 1% of eukaryotic genes code for helicases. The human genome codes for 95 non-redundant helicases: 64 RNA helicases and 31 DNA helicases. Many cellular processes, such as DNA replication, transcription, translation, recombination, DNA repair, and ribosome biogenesis involve the separation of nucleic acid strands that necessitates the use of helicases. Some specialized helicases are also involved in sensing of viral nucleic acids during infection and fulfill a immunological function. Function Helicases are of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coding Region
The coding region of a gene, also known as the coding sequence (CDS), is the portion of a gene's DNA or RNA that codes for protein. Studying the length, composition, regulation, splicing, structures, and functions of coding regions compared to non-coding regions over different species and time periods can provide a significant amount of important information regarding gene organization and evolution of prokaryotes and eukaryotes. This can further assist in mapping the human genome and developing gene therapy. Definition Although this term is also sometimes used interchangeably with exon, it is not the exact same thing: the exon is composed of the coding region as well as the 3' and 5' untranslated regions of the RNA, and so therefore, an exon would be partially made up of coding regions. The 3' and 5' untranslated regions of the RNA, which do not code for protein, are termed non-coding regions and are not discussed on this page. There is often confusion between coding region ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Analysis
In bioinformatics, sequence analysis is the process of subjecting a DNA, RNA or peptide sequence to any of a wide range of analytical methods to understand its features, function, structure, or evolution. Methodologies used include sequence alignment, searches against biological databases, and others. Since the development of methods of high-throughput production of gene and protein sequences, the rate of addition of new sequences to the databases increased very rapidly. Such a collection of sequences does not, by itself, increase the scientist's understanding of the biology of organisms. However, comparing these new sequences to those with known functions is a key way of understanding the biology of an organism from which the new sequence comes. Thus, sequence analysis can be used to assign function to genes and proteins by the study of the similarities between the compared sequences. Nowadays, there are many tools and techniques that provide the sequence comparisons (sequence al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Testing
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output. In a medical setting, genetic testing can be used to diagnose or rule out suspected genetic disorders, predict risks for specific conditions, or gain information that can be used to customize medical treatments based on an individual's genetic makeup. Genetic testing can also be used to determine biological relatives, such as a child's biological parentage (genetic mother and father) through DNA paternity testing, or be used to broadly predict an individual's ancestry. Genetic testing of plants and animals can be used for similar reasons as in humans (e.g. to assess relatedness/ancestry or predict/diagnose genetic disorders), to gain information used for selective breeding, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypopigmentation
Hypopigmentation is characterized specifically as an area of skin becoming lighter than the baseline skin color, but not completely devoid of pigment. This is not to be confused with depigmentation, which is characterized as the absence of all pigment. It is caused by melanocyte or melanin depletion, or a decrease in the amino acid tyrosine, which is used by melanocytes to make melanin. Some common genetic causes include mutations in the tyrosinase gene or OCA2 gene. As melanin pigments tend to be in the skin, eye, and hair, these are the commonly affected areas in those with hypopigmentation. Hypopigmentation is common and approximately one in twenty have at least one hypopigmented macule. Hypopigmentation can be upsetting to some, especially those with darker skin whose hypopigmentation marks are seen more visibly. Most causes of hypopigmentation are not serious and can be easily treated. Presentation Associated conditions It is seen in: * Albinism * Idiopathic guttate hypom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
