ENDO PART 2 Flashcards
If treatment is successful, most chromosome abnormalities are no longer evident in the bone marrow and as long as the karyotype appears to be normal, the patients would be said to be in
remission
At relapse, the same chromosome anomalies will reappear and may be accompanied by additional abnormalities and/or more complex cell lines, finding consistent with
disease progression
An increase in complexity over time is known as ____ and, in general, poor prognosis and severity of disease is directly correlated to the number and type of chromosome abnormalities seen.
karyotype evolution
The most common cause of mental retardation is
trisomy 21 or Down syndrome
This disorder is characterized by hypotonia, flat facies, slanted palpebral fissures, small ears, protruding tongue, transverse palmar crease, heart defects, and hypogonadism.
trisomy 21 or Down syndrome
Under 3% of patients having Down Syndrome tend to express a milder phenotype and have been shown to be ____ with two cell lines that may include a 46, XX or 46, XY line.
mosaics
A child with a translocation is often indicative of the presence of a ______, so, in these cases, karyotype analysis of both parents is generally recommended to determine if the couple is at increase risk of having additional Down syndrome children in future pregnancies.
translocation carrier parent
Trisomy 13 is also called
Patau syndrome
trisomy 18 is also called
Edward syndrome
males tend to be all and thin with relatively long legs.
Klinefelter syndrome (47, XXY)
The most common reason for referral in Sex Chromosome Aneuploidies is
- postpubertal hypogonadism;
- female-like breast development;
- infertility due to small testicles, hyalinized testicular tubules, and azoospermia.
The most commonly recognized sex chromosome aneuploidy presenting with a female phenotype is
Turner syndrome: 45,X
Also know as 4p-syndrome, is due to an apparently terminal deletion of the short arm of chromosome 4 [del(4)(p16)].
Wolf-Hirschhorn syndrome
[del(5)(p15)] is characterized by a distinctive high-pitched, cat-like cry in infancy.
Cri du chat or 5p-syndrome
Are small, they are significantly larger (>500 kb) than the typical molecular deletion
(1 base pair [bp] to several hundred bp, which can only be resolved by molecular technology.
Microdeletions
These syndromes in microdeletion are collectively called
contiguous gene syndromes
Clearly demonstrates the overlap between microdeletion and contiguous gene syndromes. The disorder has been associated with a microdeletion of the distal short arm of chromosome 17 (17p13.3). Cardinal clinical features are lissencephaly (smooth brain) and craniofacial anomalies.
Miller-Dieker syndrome
The best known of the microdeletion syndromes are
Prader-Willi syndrome (PWS) and Angelman syndormes (AS)
Patients are small and hypotonic at birth, but change within the first year of the life & begin to gain weight rapidly.
Prader-Willi
Patient, are severely mentally retarded.
Angelman syndormes (AS)
Has been associated with a deletion of the elastin gene (ELN) on the proximal long arm of chromosome 7 (7q11.23). The disorder is characterized by cardiac abnormalities, hypertension, hoarse voice, premature aging of the skin, and behavioral anomalies.
Williams syndrome
Is possibly the most common microdeletion syndrome in humans, but is often not recognized due to a broad spectrum of clinical features and a presentation that can be quite mild.
Velocardiofacial syndrome
The second leading cause of mental retardation and is the primary cause of inherited mental retardation. The mutation was identified as an amplification of a trinucleotide repeat sequence
Fragile X syndrome
Chromosomal breakage syndromes are a set of autosomal recessive disorders that were originally grouped together due to the common finding of chromosome instability or fragility.
Breakage Syndromes
