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Hoyeraal–Hreidarsson Syndrome
Hoyeraal–Hreidasson syndrome is a very rare multisystem X-linked recessive disorder characterized by excessively short telomeres and is considered a severe form of dyskeratosis congenita. Being an X-linked disorder, Hoyeraal–Hreidasson syndrome primarily affects males. Patients typically present in early childhood with cerebellar hypoplasia, immunodeficiency, progressive bone marrow failure, and intrauterine growth restriction. The primary cause of death in Hoyeraal–Hreidasson syndrome is bone marrow failure, but mortality from cancer and pulmonary fibrosis is also significant. Presentation The currently recognized features are cerebellar hypoplasia, immunodeficiency, progressive bone marrow failure, and intrauterine growth restriction. Patients also commonly exhibit symptoms such as microcephaly, aplastic anemia, and intellectual disability. Overlap with dyskeratosis congenita Patients with Hoyeraal–Hreidasson syndrome frequently present with the mucocutaneous triad of nai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-linked
Sex linkage describes the sex-specific patterns of inheritance and expression when a gene is present on a sex chromosome (allosome) rather than a non-sex chromosome ( autosome). Genes situated on the X-chromosome are thus termed X-linked, and are transmitted by both males and females, while genes situated on the Y-chromosome are termed Y-linked, and are transmitted by males only. As human females possess two X-chromosomes and human males possess one X-chromosome and one Y-chromosome, the phenotype of a sex-linked trait can differ between males and females due to the differential number of alleles (polymorphisms) possessed for a given gene. In humans, sex-linked patterns of inheritance are termed X-linked recessive, X-linked dominant and Y-linked. The inheritance and presentation of all three differ depending on the sex of both the parent and the child. This makes sex-linked patterns of inheritance characteristically different from autosomal dominance and recessiveness. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyskerin
H/ACA ribonucleoprotein complex subunit 4 is a protein that in humans is encoded by the gene ''DKC1''. Dyskerin is a pseudouridine synthase enzyme which is part of the TruB family of enzymes. Dyskerin is an L-shaped protein of 514 residues and a molecular weight of about 58 kilo- daltons. Dyskerin is essential for the activity of telomerase by accumulating telomerase RNA component (TERC). This gene is a member of the H/ACA snoRNPs (small nucleolar ribonucleoproteins) gene family. snoRNPs are involved in various aspects of rRNA processing and modification and have been classified into two families: C/D and H/ACA. The H/ACA snoRNPs also include the NOLA1, 2 and 3 proteins. The protein encoded by this gene and the three NOLA proteins localize to the dense fibrillar components of nucleoli and to coiled (Cajal) bodies in the nucleus. Both 18S rRNA production and rRNA pseudouridylation are impaired if any one of the four proteins is depleted. The protein encoded by this g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syndromes With Microcephaly
A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired with a definite cause this becomes a disease. In some instances, a syndrome is so closely linked with a pathogenesis or cause that the words ''syndrome'', ''disease'', and ''disorder'' end up being used interchangeably for them. This substitution of terminology often confuses the reality and meaning of medical diagnoses. This is especially true of inherited syndromes. About one third of all phenotypes that are listed in OMIM are described as dysmorphic, which usually refers to the facial gestalt. For example, Down syndrome, Wolf–Hirschhorn syndrome, and Andersen–Tawil syndrome are disorders with known pathogeneses, so each is more than just a set of signs and symptoms, despite the ''syndrome'' nomenclature. In other instances, a syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare Genetic Syndromes
Rare may refer to: * Rare, a particular temperature of meat * Something infrequent or scarce, see Scarcity :* Rare species, a conservation category in biology designating the scarcity of an organism and implying a threat to its viability Rare or RARE may also refer to: Acronyms * Ram Air Rocket Engine, a U.S. Navy program of the 1950s *Ronne Antarctic Research Expedition Music * Rare (Northern Irish band), a 1990s trip hop group * Rare (Serbian band), an alternative rock band Albums * ''Rare'' (Asia album), 1999 * ''Rare'' (David Bowie album), 1982 * ''Rare'' (Hundredth album), 2017 * ''Rare'' (Selena Gomez album) or the title song (see below), 2020 * '' Rare!'', by Crack the Sky, 1994 * '' Rare, Vol. 1'', by Ultravox, 1993 * '' Rare, Vol. 2'', by Ultravox, 1994 * ''Rare: The Collected B-Sides 1989–1993'', by Moby, 1996 * ''Rare'', by Xiu Xiu, 2012 Songs * "Rare" (Gwen Stefani song), 2016 * "Rare" (Selena Gomez song), 2020 * "Rare", by Man Overboard from ''Man Ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-linked Recessive Disorders
Sex linkage describes the sex-specific patterns of Heredity, inheritance and Gene expression, expression when a gene is present on a sex chromosome (allosome) rather than a non-sex chromosome (autosome). Genes situated on the X chromosome, X-chromosome are thus termed X-linked, and are transmitted by both males and females, while genes situated on the Y chromosome, Y-chromosome are termed Y-linked, and are transmitted by males only. As human females possess two X-chromosomes and human males possess one X-chromosome and one Y-chromosome, the phenotype of a sex-linked trait can differ between males and females due to the differential number of alleles (polymorphisms) possessed for a given gene. In humans, sex-linked patterns of inheritance are termed X-linked recessive, X-linked dominant and Y-linked. The inheritance and presentation of all three differ depending on the sex of both the parent and the child. This makes sex-linked patterns of inheritance characteristically different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyskeratosis Congenita
Dyskeratosis congenita (DKC), also known as Zinsser-Engman-Cole syndrome, is a rare progressive congenital disorder with a highly variable phenotype. The entity was classically defined by the triad of abnormal skin pigmentation, nail dystrophy, and leukoplakia of the oral mucosa, and myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML), but these components do not always occur. DKC is characterized by short telomeres. The disease initially can affect the skin, but a major consequence is progressive bone marrow failure which occurs in over 80%, causing early mortality. Presentation DKC can be characterized by cutaneous pigmentation, premature graying, dystrophy of the nails, leukoplakia of the oral mucosa, continuous lacrimation due to atresia of the lacrimal ducts, often thrombocytopenia, anemia, testicular atrophy in the male carriers, and predisposition to cancer. Also, liver abnormalities are associated with this syndrome, Nodular Regenerative Hypoplasia of the liv ... [...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 breed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PARN
Poly(A)-specific ribonuclease (PARN), also known as polyadenylate-specific ribonuclease or deadenylating nuclease (DAN), is an enzyme that in humans is encoded by the ''PARN'' gene. Function Exonucleolytic degradation of the poly(A) tail is often the first step in the decay of eukaryotic mRNAs. The amino acid sequence of poly(A)-specific ribonuclease shows homology to the RNase D family of 3'-exonuclease Exonucleases are enzymes that work by cleaving nucleotides one at a time from the end (exo) of a polynucleotide chain. A hydrolyzing reaction that breaks phosphodiester bonds at either the 3′ or the 5′ end occurs. Its close relative is th ...s. The protein appears to be localized in both the nucleus and the cytoplasm. It is not stably associated with polysomes or ribosomal subunits. Hereditary mutations in PARN lead to the bone marrow failure disease dyskeratosis congenita which is caused by defective telomerase RNA processing and degradation in patients. Ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ACD (gene)
Adrenocortical dysplasia protein homolog is a protein that in humans is encoded by the ''ACD'' gene. Function This gene encodes a protein that is involved in telomere function. This protein is one of six core proteins in the telosome/shelterin telomeric complex, which functions to maintain telomere length and to protect telomere ends. Through its interaction with other components, this protein plays a key role in the assembly and stabilization of this complex, and it mediates the access of telomerase to the telomere. Multiple transcript variants encoding different isoforms have been found for this gene. This gene, which is also referred to as TPP1, is distinct from the unrelated TPP1 gene on chromosome 11, which encodes tripeptidyl-peptidase I. TPP1 is a component of the telomere-specific shelterin complex, which facilitates the replication of the double-stranded telomeric DNA tracts and protects the telomeric end from unregulated DNA repair activities. TPP1 mainly functions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TINF2
TERF1-interacting nuclear factor 2 is a protein that in humans is encoded by the ''TINF2'' gene. TINF2 is a component of the shelterin protein complex found at the end of telomeres. Interactions TINF2 has been shown to interact with ACD, POT1 Protection of telomeres protein 1 is a protein that in humans is encoded by the ''POT1'' gene. Function This gene is a member of the telombin family and encodes a nuclear protein involved in telomere maintenance. Specifically, this protein fu ... and TERF1. References Further reading * * * * * * * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Dyskeratosis CongenitaPDBe-KBprovides an overview of all the structure information available in the PDB for Human TERF1-interacting nuclear factor 2 (TINF2) Telomere-related proteins {{gene-14-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
