Chromosomal Syndromes: Cri du Chat Syndrome

Transcription

1 Chromosomal Syndromes: Cri du Chat Syndrome

2 Chromosomal Syndrome: Cri du Chat (Karotype) Cri du Chat syndrome is caused by a deletion of the end of the short arm of chromosome 5 (written as 5p-). Identified by J Lejeune in 1963 (French geneticist)

3 Cri du Chat: Karotype French term for cry of the cat because of the high pitched cry and voice.

4 Cri du Chat: Phenotype 1 of every 50,000 births Occurs as a random event during formation of reproductive cells or early fetal development. Small size at birth Microcephaly (including larynx) High palate or possible cleft Hypertolerism Ptosis (epicanthic folds) Mental disability (likely severe) Chronic otitis media Delayed motor development Normal life expectancy

5 Cri du Chat

6 Cri du Chat: Phenotype

7 Cri du Chat: Communication Oral speech seldom develops Severe language disorder Possible hypernasality Possible hearing loss Children tend to be loving & very social

8 Cri du Chat: Communication

9 Genetic Syndrome: Crouzon Syndrome Photo from M.O. Crouzon's original publication

10 Genetic Syndrome: Crouzon Syndrome (Karotype) Caused by mutations in a specific gene (FGFR2) located on Chromosome 10. The gene is associated with growth factors in face and skull. Identified by Crouzon in 1912 (French neurosurgeon).

11 Crouzon Syndrome Characterized by abnormalities of skull & face, and hands & feet. There is premature closure of some of the sutures of the skull (craniosynostosis) resulting in an abnormally shaped head and an abnormally shaped face with shallow eye sockets and under-development of the midface. Technical name is Craniofacial Dysostosis

12 Crouzon Syndrome: Phenotype Premature fusion of cranial sutures Mid-face hypoplasia (underdeveloped) Beak-shaped nose Exorbitism (bulging eyes) Low-set ears Class III malocclusion Possible otitis media Mental disability is rare

13 Crouzon Syndrome Occurs in 1 out of every 60,000 births Normal life expectancy No sex differences Craniectomy to correct skull abnormalities Facial reconstruction to correct mid-face abnormalities Schematic of procedure to advance the forehead and middle third of the face

14 Craniofacial Reconstruction Young woman before and after surgery to correct orbital and maxillary abnormalities Two-year-old boy before and after surgery to extend forehead/brow

15 Crouzon Syndrome: Post-Operative

16 Crouzon Syndrome: Post-Op

17 Crouzon Syndrome: Communication Normal onset of speech and language Articulation disorder resulting from Class III Hyponasality due to small nasal port Possible otitis media leading to hearing loss

18 Genetic Syndromes: Foetal Alcohol Syndrome

19 "Of all the substances of abuse, including heroin, cocaine, and marijuana, alcohol produces by far the most serious neurobehavioral effects in the fetus. --Institute of Medicine 1996 Report to Congress Fetal Alcohol Syndrome by Anuppa Caleekal (1996)

20 Some Facts about Alcohol Legally intoxicated is defined as a Blood Alcohol Level (BAL) of.08%. Permanent brain cell damage begins at a BAL of.07%. A 100 lb (45 kg) female consuming 5 standard drinks will reach a BAL of.25% - three times the legal limit. BAL reduces.01% per hour. A drink equals a 12 oz. regular beer, 1.5 oz. shot of 80 proof liquor, or 4 oz. glass of regular table wine.

21 Alcohol as a Teratogen Foolish, drunken, or harebrain women most often bring forth children like unto themselves Aristotle in Problemata ( bc)

22 FAS: Karotype Ethanol (drinking alcohol) alone is found to interact with over 1000 genes & cell events. Difficult to pinpoint the exact gene (and how the gene is mutated) because of issues related to amount, time of consumption, and interaction with other drugs. A gene array

23 Effects of Alcohol as a Teratogen on the Baby

24 3 out of 5 women drink alcohol Women metabolize alcohol quicker than men and get intoxicated more easily. When women are pregnant (and drink) the foetus receives a strong dose of alcohol. 3 in 1000 births show full signs of FAS 10 in 1000 births show some signs, called Foetal Alcohol Effects (FAE) Type & severity of condition is dependent on when abuse occurred: Early in pregnancy will affect foetal development of face, limbs, cardiac & brain development Late in pregnancy will affect brain (IQ)

25 FAS: Phenotype 50% or more cases of FAS show: Below average height & weight Microcephaly Micrognathia Poor fine & gross motor coordination Thin upper lip No philtrum Short, upturned nose Hyperactivity Cognitive impairment Shortened (and bent) little finger

26 FAS: Phenotype

27 FAS: Communication General delay in communication development Articulation problems due to poor motor coordination Language delay due to possible intellectual impairments Possible swallowing difficulties Possible otitis media

28