Autosomal Aberrations

AUTOSOMALAberrations

CRISTOBAL, Erica Joyce B.JARABE, Renee Beatriz P.AAPD2B

OBJECTIVESAt the end of the unit, the students should be able to:

1. Understand the importance of human karyotyping2. Characterize individuals with sex chromosome

aberrations3. Differentiate the types of autosomal aberrations,

and4. Illustrate and explain the different structural

abnormalities

UNIT V. Human Chromosomes and Chromosome Behavior

CHROMOSOMAL ABERRATIONS / ABNORMALITIES* * *

*It is the disruptions in the normal chromosomal content of a cell.

*Originates as a result of an error during meiosis (Non-Disjunction), specifically in ANAPHASE stage.

* * *

Wolf-Hirschhorn Syndrome

Wolf-Hirschhorn Syndrome (WHS) , also known as Pitt-Rogers-Danks Syndrome or Pitt Syndrome ----- was first described in 1961 by Americans Herbert L. Cooper and Kurt Hirschhorn and thereafter, gained worldwide attetion by publications by the German Ulrich Wolf and Hirschhorn, Humangenetik a German scientific magazine.

DELETION of the short arm of chromosome 4.

*Short Philtrum*Immunodeficient*Microcephaly (Small Head Size)*Seizures *Muscle Hypotonia*Renal Anomalies*Deafness

Physical Characteristics

Cri Du Chat

CRI DU CHAT also known as chromosome 5p deletion syndrome, 5p minus syndrome or Lejeune’s syndrome.

*Is a rare genetic disorder due to a missing part of chromosome 5. Its name is a French term (cat-cry or call of the cat) referring to the characteristic cat-like cry of affected children.

*It was first described by Jerome Lejeune in 1963. The condition affects an 1 in 50,000 live births, strikes all ethnicities, and is more common in females by a 4:3 ratio.

DELETION on the short arm of chromosome 5.Cries like a CAT

*Excessive Drooling*Behavioral Problems*Often Mental Retarded*Exhibits Gastorintestinal and

Cardiac Complications*Abnormal Development of

Larynx and Glottis


Jacobsen’s Syndrome

Jacobsen’s Syndrome also known as 11q deletion disorder, is a rare congenital disorder resulting from deletion of a terminal region of chromosome 11 that includes band 11q24.1.

*It can cause intellectual disabilities, a distinctive facial appearance, and a variety of physical problems including heart defects and a bleeding disorder.

*The syndrome was first identified by Danish physician Petra Jacobsen, and is believed to occur in approximately 1 out of every 100,000 births.

is a condition caused by the DELETION of a terminal region of chromosome 11.

*Bleeding Disorder*Heart Defects*Wide Set Eyes*Low Set Misshapen Ears*Large Toes


Pallister-Killian Syndrome

Pallister-Killian Syndrome also known as Tetrasomy 12p Mosaicism or Pallister Mosaic Aneuplody Syndrome.

Is an extremely rare genetic disorder occurring in humans. Pallister-Killian occurs due to the presence of the anomalous extra isochromosome 12p, the short arm of the twelfth chromosome.

This leads to the development of Tetrasomy 12p. Because not all cells have the extra isochromosome, Pallister-Killian is a mosaic condition.

TETRASOMY in the smaller arm of chromosome 12.

2n+2 or 48 chromosomes

*Hypo/Hyper Pigmentation*Epilepsy*High Foreheads*Flat nose*Supernumerary Nipples*Psychomotor Retardation


Patau Syndrome

Patau Sundrome, also known as Trisomy 13 and Trisomy D.

*Is a chromosomal abnormality, a syndrome in which a patient had an additional chromosome 13 due to non-disjunction of chromosomes during meiosis. Some are caused by Robertsonian Translocations. The extra chromosome 13 disrupts the normal course of development, causing heart and kidney defects, amongst other features characteristic of Patau syndrome.

*Patau syndrome affects somewhere between 1 in 10,000 and 1 in 21,700 live births.

TRISOMIC in the chromosome 13.47 chromosomes

*Polydactyl*Cleft Palate*Cutis Aplasia*Kidney Failures


IDIC 15 (Isodi

Centic 15)

Isodicentric chromosome 15 is the scientific name for a specific type of chromosome abnormality. Individuals with isodicentric chromosome 15, or "idic(15)", have 47 chromosomes instead of the typical 46 chromosomes.

With extra genetic material in chromosome 15.47 chromosomes

*Epicanthal Folds in the Eye*Short Stature*Delayed Language Development*Seizures*Some are Mentally Retarded


Edward’s Syndrome

Edward’s Syndrome also kwnon as Trisomy 18 (T18) or Trisome E.

*It is a genetic disorder caused by the presence of all of an extra 18th chromosome (Trisomy 18).

*It is named after John H. Edwards, who first described the syndrome in 1960. It is the second most common autosomal trisomy, after Down Syndrome, that carries to term.

*Edward’s Syndrome occurs in around one in 6,000 live births and around 80 % of those affected are female.

*Upturned Nose*Kidney Malformations*Omphalocele*Arthrogryposis*Microcephaly*Underdeveloped Phalanges


Down Syndrome

Down Syndrome also known as Trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th century by Jean Etienne Dominique Esquirol in 1838 and Edouard Seguin in 1844. Down syndrome was identified as a chromosome 21Trisomy by Dr. Jerome Lejeune in 1959.

*The average IQ of children with Down syndrome is around 50, compared to normal children with an IQ of 100.

With extra genetic material in chromosome 15.47 chromosomes

*Epicanthal Folds in the Eye*Short Stature*Delayed Language Development*Seizures*Some are Mentally Retarded


Cat Eye Syndrome

Cat Eye Syndrome is a rare condition caused by the short arm (p) and a small section of the long arm (q) of human Chromosome 22 being present three (trisomic) or four times (tetrasomic) instead of the usual two times.

*The term "Cat Eye" syndrome was coined because of the particular appearance of the vertical colobomas in the eyes of some patients. However, over half of the CES patients in the literature do not present with this trait.

*There is no significant reduction in life expectancy in patients who are not afflicted with one of CES' life threatening abnormalities.

*Iris Coloboma*Slant Opening of the Eyelids*Abnormal Obstruction of the Anus*Scoliosis*Hernias


Health & Medicine

Autosomal Aberrations