Chromosome abnormalities and clinical phenotypes Flashcards
(14 cards)
What do most autosomal aberrations induce?
Consistent recognizable patterns of multiple malformations, minor anomalies, and phenotypes with variable degrees of developmental disability.
What are some well-known chromosome syndromes?
- Down syndrome
- Edwards syndrome
- Patau syndrome
- Turner syndrome
What is a common characteristic of phenotypic variability in chromosome syndromes?
No one patient has every feature; most congenital malformations are seen in only some affected individuals.
What underscores the need for chromosome analysis when clinical features suggest a chromosome abnormality?
Phenotypic variability and the potential for misdiagnosis.
What biological mechanism is often associated with milder expression of chromosome abnormalities?
Mosaicism.
What generalization can be made about most chromosome abnormalities?
They are associated with developmental delay in children and intellectual disability in older persons.
Why do chromosome abnormalities likely affect nervous system development?
A large number of human genes, perhaps one-third or more of the total, participate in the development of the central nervous system.
How do chromosome syndromes typically affect facial features?
They involve alterations of facial morphogenesis that produce characteristic facial features.
What is commonly seen in autosomal syndromes regarding growth?
Growth delay (short stature and/or poor weight gain in infancy).
What type of congenital malformations occur with increased frequency in most autosomal chromosome disorders?
Congenital heart defects.
What is the most common clinical indication for a chromosome analysis?
A newborn with multiple congenital malformations or a child with developmental delay.
What can chromosome abnormalities typically result in?
Developmental delay, intellectual disability, characteristic facial features, and various types of congenital malformations.
True or False: Many chromosome abnormalities can be recognized by clinical examination.
True.
Fill in the blank: A chromosome analysis is indicated for a newborn with _______ or a child with developmental delay.
multiple congenital malformations
