Mutations with the genome Flashcards
How does genes and human disease work
50% of the spontaneous abortions during the early months of gestation have a demonstrable chromosomal abnormality
1% of all newborn infants possess a gross chromosomal abnormality
5% of individuals under 25 develop a serious disease with a significant genetic component the genetic disease encountered in medical practice represent only the tip of the iceberg.
What are genes
the basic unit of heredity in living cells. they consist of length of DNA that contain instructions or codes that make protein. through the proteins come genes that influence everything. not all the cells have active genes.
What are the two types of diseases?
Hereditary and Congenital
What are hereditary disease
one parents and are transmitted in the germ line through the generation and therefore are familial
What are congenital disease
simply “born with it” some not genetic.
What are the classification of genetic disorders?
Disorders related to mutant genes of large effect
disease with multifactorial inheritance
chromosomal disorders
What is chromosomal disorders
results from genomic or chromosomal mutation and are therefore associated with numerical or structural changes in the chromosomes
What are disease with multifactorial inheritance
include some of the most common diseases of human like hypertension and diabetes. they are called multifactorial because they are influenced by the genetics and the environmental factors.
What are Disorders related to mutant genes of large effect
Mendelian. includes many relatively uncommon conditions that result from signs gene mutation of large effect. most of these follow the classic mendelian patterns of inheritance and so they are referred to as mendelian disorders
Haploid is?
one set of chromosomes
diploid is
contains two complete set of chromosomes
What is the structure of the chromosome?
all chromosomes have 2 arms (short and long) P=short and Q=long
What are the different types of chromosome structure
the centromere is either metacentric( almost equal in arm length) or acrocentric (uneven tend to be 13,14,15,21,22).
What are karotypes
the sum of all the chromosome information or the observed characteristics of the chromosome of an individual or species.
What are the normal karoytypes
contains 22 paris of autosomal chromosomes and one pari of sex chromosomes
what is normal karyotypes for a woman?
contains 2 X chromosome and a denoted 46,XX. Men are X and Y denoted 46,XY. there can be some abnormal numbers and that meaning disorders like 47,XYY or 47,XXX or 45,X0
What are the different types of chromosomes abnormalities?
Numerical and Structural
What are the types of numerical disorders
Mosaicism, Aneuploidy and Polyploidy
What are the types of structural disorders
Deletion, Inversion and Translocatoin
What is mosaicism
denotes presence of 2 population of cells with different karyotypes in one individual . mitotic errors in early development give rise to 2 or more population of cells in the same individual
What is aneuploidy
is a change in the number of the chromosomes that can lead to a chromosomal disorder. chromosome complement that is not an exact multiple of 23. the mechanism is nondisjunction and anaphase lag. increase material age causes this.
What is the entire Human Genome?
has been sequenced but less than 2% encode proteins. about 20-25,000 genes code for proteins. about 100,00 can be encoded through alternative splicing
About half of the human genome consist of blocks of repetitive DNA Sequences.
Any 2 people share >99.5% of their DNA sequence and the diversity of humans is encode in
What are the two types of DNA variation
SNP
CNV’s
What is Single Nucleotide Polymorphism
A single nucleotide polymorphism, also known as simple nucleotide polymorphism, (SNP, pronounced snip; plural snips) is a DNA sequence variation occurring commonly within a population (e.g. 1%) in which a single nucleotide — A, T, C or G — in the genome (or other shared sequence) differs between members of a biological species or paired chromosomes. For example, two sequenced DNA fragments from different individuals, AAGCCTA to AAGCTTA, contain a difference in a single nucleotide. In this case we say that there are two alleles. Almost all common SNPs have only two alleles.
What is Copy-number variation
a form of structural variation—are alterations of the DNA of a genome that results in the cell having an abnormal or, for certain genes, a normal variation in the number of copies of one or more sections of the DNA. CNVs correspond to relatively large regions of the genome that have been deleted (fewer than the normal number) or duplicated (more than the normal number) on certain chromosomes. For example, the chromosome that normally has sections in order as A-B-C-D might instead have sections A-B-C-C-D (a duplication of “C”) or A-B-D (a deletion of “C”).
What is epigenetics
heritable changes in gene expression that are not caused by alterations in DNA sequence. Involved in tissue specific expression of Genes and genomic imprinting
What is epigenome?
it is distinct chromatin compositions. it distinguish different cell types, respond to intrinsic and external signal, DNA methylation, histone modifications, nucleosome, remodeling, exchange of histone, variant, and non-coding RNA
What is non coding RNA?
A non-coding RNA (ncRNA) is an RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA (npcRNA), non-messenger RNA (nmRNA) and functional RNA (fRNA). The DNA sequence from which a functional non-coding RNA is transcribed is often called an RNA gene.Class of genes that encode small RNA molecules: micro RNA (miRNA)
What are the types of Non-coding RNA
Long noncoding RNA
Micro RNA
What is long noncode RNA
Long non-coding RNAs (long ncRNAs, lncRNA) are non-protein coding transcripts longer than 200 nucleotides.[1] This somewhat arbitrary limit distinguishes long ncRNAs from small regulatory RNAs such as microRNAs (miRNAs), short interfering RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), and other short RNAs.[2]
What are microRNA
micro RNA (abbreviated miRNA) is a small non-coding RNA molecule (containing about 22 nucleotides) found in plants, animals, and some viruses, which functions in RNA silencing and post-transcriptional regulation of gene expression.[1][2] don’t not encode protein and it inhibits gene expression by silencing gene expression.
What makes the noncoding RNA inactivate
Xist
