Down syndrome, or trisomy Trisomy The possession of a third chromosome of any one type in an otherwise diploid cell. Types of Mutations 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR), gastrointestinal, ocular, and auditory systems. Characteristic traits include upslanting, almond-shaped eyes with skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions covering the inner aspects, broad flattened nasal bridge, small rounded ears, and small mouth with large tongue Tongue The tongue, on the other hand, is a complex muscular structure that permits tasting and facilitates the process of mastication and communication. The blood supply of the tongue originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy. Screening Screening Preoperative Care for Down syndrome occurs during the 1st and 2nd trimesters of pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care and includes both blood tests and prenatal ultrasonography. Ultimately, karyotyping Karyotyping Mapping of the karyotype of a cell. Chromosome Testing confirms diagnosis in the prenatal or postnatal period Postnatal period Prenatal and Postnatal Physiology of the Neonate. There is no cure for Down syndrome. Treatment is based on the clinical manifestations present; it includes a strong support system and early intervention programs to help with education and development.
Last updated: 10 Mar, 2022
There are 3 genotypes that result in Down syndrome.
Karyotype
Karyotype
The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere.
Congenital Malformations of the Female Reproductive System of
trisomy
Trisomy
The possession of a third chromosome of any one type in an otherwise diploid cell.
Types of Mutations 21 (Down syndrome):
A
karyotype
Karyotype
The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere.
Congenital Malformations of the Female Reproductive System is a laboratory technique in which an individual’s
chromosomes
Chromosomes
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell.
DNA Types and Structure are paired and photographed. In a patient with Down syndrome, 3 copies of
chromosome
Chromosome
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell.
Basic Terms of Genetics 21 are usually visible.
Scheme of a genetic mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations, in this case of trisomy Trisomy The possession of a third chromosome of any one type in an otherwise diploid cell. Types of Mutations 21
Image: “ Genome Genome The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics scheme of trisomy Trisomy The possession of a third chromosome of any one type in an otherwise diploid cell. Types of Mutations 21” by National Human Genome Genome The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics Research Research Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. Conflict of Interest Institute. License: Public DomainDown syndrome translocation
Image: “Down syndrome translocation” by National Human Genome Genome The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics Research Research Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. Conflict of Interest Institute. License: Public Domain
Robertsonian translocation
Robertsonian translocation
Patau Syndrome (Trisomy 13) of Down syndrome in families:
In a
Robertsonian translocation
Robertsonian translocation
Patau Syndrome (Trisomy 13) causing Down syndrome, part of an extra or a whole extra
chromosome
Chromosome
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell.
Basic Terms of Genetics 21 is attached (translocated) to another
chromosome
Chromosome
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell.
Basic Terms of Genetics. Individuals who inherit this
chromosome
Chromosome
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell.
Basic Terms of Genetics have 3 copies of the genetic material found on
chromosome
Chromosome
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell.
Basic Terms of Genetics 21, and thus have Down syndrome.
Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor of Down syndrome
Image by Lecturio.The eyes of a baby with Down syndrome:
Brushfield spots are visible between the inner and outer circles of the
iris
Iris
The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers – the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium.
Eye: Anatomy.
High prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency of ocular disorders: Frequency increases with age.
Feet of a 10-year-old boy with Down syndrome, with the typical large space between the large toe and the second toe
Image: “Feet of a boy with Down syndrome” by Loranchet. License: CC BY 3.0Screening Screening Preoperative Care is recommended prior to 20th week of gestation.
Trisomy
Trisomy
The possession of a third chromosome of any one type in an otherwise diploid cell.
Types of Mutations 21 on ultrasound:
Ultrasound image of fetus at 12 weeks, showing
nuchal translucency
Nuchal translucency
A prenatal ultrasonography measurement of the soft tissue behind the fetal neck. Either the translucent area below the skin in the back of the fetal neck (nuchal translucency) or the distance between occipital bone to the outer skin line (nuchal fold) is measured.
Obstetric Imaging and presence of nasal
bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types
Given the pervasive nature of Down syndrome and the lack of a cure, the majority of management focuses on screening Screening Preoperative Care and prevention of the various clinical manifestations and complications associated with the syndrome.