7q11.23 Duplikationssyndrom: MedlinePlus Genetics (2023)

FAQs

What is 7q11 23 duplication syndrome karyotype? ›

7q11. 23 duplication syndrome results from an extra copy of a region on the long (q) arm of chromosome 7 in each cell. This region is called the Williams-Beuren syndrome critical region (WBSCR) because its deletion causes a different disorder called Williams syndrome, also known as Williams-Beuren syndrome.

MECP2 duplication syndrome is a condition that occurs almost exclusively in males and is characterized by moderate to severe intellectual disability. Most people with this condition also have weak muscle tone in infancy, feeding difficulties, poor or absent speech, or muscle stiffness (rigidity).

Distal trisomy 11q is a rare chromosomal anomaly syndrome, resulting from the partial duplication of the long arm of chromosome 11, with high phenotypic variability principally characterized by craniofacial dysmorphism (brachycephaly/plagiocephaly, low-set, posteriorly rotated ears, short philtrum, micrognathia) and ...

A 7q duplication is a rare genetic condition that occurs when there is an extra copy of part of the genetic material (DNA) in one of the 46 chromosomes – chromosome 7. This extra copy is known as a duplication, sometimes referred to as a copy number gain.

Williams syndrome is caused by not having a copy of 25 to 27 genes on chromosome number 7. In most cases, the gene changes (mutations) occur on their own, either in the sperm or egg that a baby develops from. However, once someone carries the genetic change, their children have a 50% chance of inheriting it.

Gene duplications can arise as products of several types of errors in DNA replication and repair machinery as well as through fortuitous capture by selfish genetic elements. Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage.

Gene duplications are an essential source of genetic novelty that can lead to evolutionary innovation. Duplication creates genetic redundancy and if one copy of a gene experiences a mutation that affects its original function, the second copy can serve as a 'spare part' and continue to function correctly.

MECP2 duplication syndrome (MDS) is a rare, X-linked, neurodevelopmental disorder caused by a duplication of the methyl-CpG-binding protein 2 (MECP2) gene—a gene in which loss-of-function mutations lead to Rett syndrome (RTT). MDS has an estimated live birth prevalence in males of 1/150,000.

A 7q11. 23 duplication means that the cells of the body have a small amount of additional genetic material from one of their 46 chromosomes – chromosome 7. For healthy development, chromosomes should contain just the expected amount of genetic material (DNA) – not too much and not too little.

These include small and low-set ears, widely set eyes (hypertelorism ) with droopy eyelids (ptosis ), skin folds covering the inner corner of the eyes (epicanthal folds ), a broad nasal bridge , downturned corners of the mouth , a thin upper lip , and a small lower jaw .

What does chromosome 11 control? ›

Many of the genes on chromosome 11 are grouped into related clusters known as gene families, the most notable of which is the olfactory receptor gene family. This family, whose corresponding proteins govern the sense of smell, is the largest known grouping of genes in vertebrate species.

The term "duplication" simply means that a part of a chromosome is duplicated, or present in 2 copies. This results in having extra genetic material, even though the total number of chromosomes is usually normal.

Trisomy 7 is a condition that is caused by an extra chromosome number 7 (three copies instead of two). What are the features of trisomy 7? Most pregnancies with trisomy 7 will miscarry spontaneously. Full trisomy 7 has never been reported in a live birth.

Fetal death in utero may occur due to the high percentage of trisomy 7 cells in the placenta or the presence of trisomy 7 cells in the fetus [7]. Hsu et al. [26] reported a case with 100% trisomy 7 cells in the villi from the placenta, which ultimately terminated in fetal death.

Chromosome 7 is one of the 23 pairs of chromosomes in humans, who normally have two copies of this chromosome. Chromosome 7 spans about 160 million base pairs (the building material of DNA) and represents between 5 and 5.5 percent of the total DNA in cells. Human chromosome 7 pair after G-banding.

Down syndrome is also referred to as Trisomy 21. This extra copy changes how the baby's body and brain develop, which can cause both mental and physical challenges for the baby.

Chromosome 7 is frequently associated with chromosome aberrations, rearrangements, and deletions. It also contains many important genes, gene families, and disease loci.

Inheritance. Most cases of Williams syndrome are not inherited. The chromosomal alteration usually occurs as a random event during the formation of reproductive cells (eggs or sperm) in a parent of an affected individual. These cases occur in people with no history of the disorder in their family.

Even claims about very low IQ turn out to be exaggerated. Williams syndrome IQ ranges from 48 to 85. True, people with Williams syndrome are often very loquacious and usually have better language than spatial skills, but the profile of the syndrome is unscientifically exaggerated by secondary sources.

Williams syndrome is a rare disorder that affects males and females in equal numbers and infants of any race may be affected. The prevalence of this disorder is approximately one in 10,000-20,000 births in the United States.

What is chromosome 17q11 2 duplication syndrome? ›

Summary. 17q11 microdeletion syndrome is a rare severe form of neurofibromatosis type 1 (NF1; see this term) characterized by mild facial dysmorphism, developmental delay, intellectual disability, increased risk of malignancies, and a large number of neurofibromas.

Williams syndrome (WS) is a developmental disorder with variable phenotypic expression associated, in most cases, with a hemizygous deletion of part of chromosomal band 7q11. 23 that includes the elastin gene (ELN).

Females have two X chromosomes (46,XX), and males have one X and one Y chromosome (46,XY). Most often, boys and men with Klinefelter syndrome have the usual X and Y chromosomes, plus one extra X chromosome, for a total of 47 chromosomes (47,XXY).

Trisomy 18 is rare, occurring in about 1 in 2,500 pregnancies. The cells of these babies have three copies of chromosome 18 instead of the usual two. There is no cure. Most babies with trisomy 18 die before they are born.

Duplication. The type IA form of Charcot-Marie-Tooth disease is an example of an inherited human genetic disease that's caused by a gene duplication. Individuals with Charcot-Marie-Tooth disease have damage to their peripheral nerves, resulting in muscle weakness.

The seventh pair of chromosomes has a gene called the CFTR (cystic fibrosis transmembrane conductance regulator) gene. Changes (mutations) or errors in this gene are what cause CF.

There are 2 types of chromosome, called the sex chromosomes, that determine the genetic sex of a baby. These are named either X or Y. Usually, a female baby has 2 X chromosomes (XX) and a male has 1 X and 1 Y (XY). But in Klinefelter syndrome, a boy is born with an extra copy of the X chromosome (XXY).

Klinefelter syndrome only affects males. It happens because of a difference deep inside the body's cells, in microscopic strings of DNA (what make up genes) called chromosomes. Chromosomes are tiny, but they play a huge role in who we are — including deciding our gender, how we look, and how we grow.

Overview. Turner syndrome, a condition that affects only females, results when one of the X chromosomes (sex chromosomes) is missing or partially missing. Turner syndrome can cause a variety of medical and developmental problems, including short height, failure of the ovaries to develop and heart defects.