Klinefelter Syndrome Overview

30 Questions

Which syndrome is characterized by tall stature, small testes, gynaecomastia, slightly lower IQ, and infertility?

Klinefelter Syndrome

What is the IQ range typically observed in individuals with 47,XXX?

80-90

Which gene on Xp21 is associated with Duchenne muscular dystrophy (DMD) and mental retardation?

Steroid sulfatase gene (STS)

Individuals with tiny ring X syndrome exhibit severe mental retardation due to what condition?

Absence of XIST gene

In an unbalanced female X-autosome carrier with 46,X,der(X),t(X;autosome), which chromosome segment should usually be preferentially inactivated?

The X chromosome segment containing XIC

Which genetic disorder is associated with the DMD gene at Xp21?

Duchene/Becker muscular dystrophy

What is the consequence of disruption of sex vesicle in males with a balanced male X-autosome carrier?

Infertility due to spermatogenic arrest

Which chromosomal abnormality results in X nullisomy and autosomal trisomy in males?

46,Y,der(X),t(X;autosome)

Which gene is associated with lissencephaly located at Xq22.3?

XLIS

In genetics, what does the term 'derivative' chromosome refer to?

Modified or altered version of a chromosome

Match the following genetic disorders with their associated genes:

Duchenne muscular dystrophy (DMD) = Xp21 X-linked ichthyosis = Xp22.3 Hypogonadism and anosmia = Kallmann gene (ANOS1) Skeletal dysplasia = CDPX gene

Match the following chromosomal abnormalities with their characteristics:

47,XXY Klinefelter syndrome = Tall stature 47,XXX Triple X syndrome = IQ 82, learning difficulties, impaired speech 47,XYY syndrome = Normal IQ, minor learning difficulties, behavioral issues Tiny ring X syndrome = Severe mental retardation due to functional X disomy

Match the following phenotypes with their corresponding chromosomal configurations:

Balanced female X-autosome carrier = 46,X,t(X;autosome) Unbalanced female X-autosome carrier = 46,X,der(X),t(X;autosome) Partial Turner syndrome = FEMALES 48,XXXY and 49,XXXXY severe retardation = Klinefelter syndrome

Match the following characteristics with their corresponding syndromes:

Small testes, gynaecomastia, infertility = 47,XXY Klinefelter syndrome Mostly normal phenotype with lower IQ and fertility issues = 47,XXX Triple X syndrome Mostly normal phenotype with tall stature and minor learning difficulties = 47,XYY syndrome Rare severe retardation with extra X chromosomes = 48,XXXY and 49,XXXXY

Match the following genes with their associated conditions:

Duchenne muscular dystrophy (DMD) = Xp21 Steroid sulfatase gene (STS) = X-linked ichthyosis Kallmann gene (ANOS1) = Hypogonadism and anosmia CDPX gene = Skeletal dysplasia

Match the following with their consequences in males with unbalanced male X-autosome carrier (46,Y,der(X),t(X;autosome)):

X nullisomy = Not viable Autosomal trisomy = Not viable Disruption of sex vesicle = Presumed mechanism for infertility Derivative chromosome formation = Formation due to genetic events

Match the following terms with their associated genetic disorder:

DMD gene at Xp21 = Duchenne/Becker muscular dystrophy Lissencephaly gene XLIS at Xq22.3 = Lissencephaly X-linked Mendelian disorders classic historical example = Duchenne/Becker muscular dystrophy Premature ovarian failure to primary amenorrhea = Ovarian dysfunction

Match the following descriptions with the appropriate term:

Critical regions at Xq13-q22 and Xq22-q27 breakpoints affecting ovarian function = X-linked Mendelian disorders Invariably infertile due to spermatogenic arrest = Balanced male X-autosome carrier Exposed to classic historical example of Duchene/Becker muscular dystrophy at Xp21 = Disruption of X loci Modified or altered version of a chromosome = Derivative chromosome

Match the following chromosomal abnormalities with their consequences:

46,Y,t(X;autosome) = Invariably infertile 46,X,der(X),t(X;autosome) = Not viable due to X nullisomy and autosomal trisomy

Match the following terms with their associated symptoms or characteristics:

Tiny ring X syndrome = Severe mental retardation Balanced male X-autosome carrier (46,Y,t(X;autosome)) = Spermatogenic arrest leading to infertility Unbalanced female X-autosome carrier (46,X,der(X),t(X;autosome)) = Preferential inactivation of a specific chromosome segment Male with disruption of sex vesicle due to balanced male X-autosome carrier = "Presumed mechanism for infertility"

What is the classic historical example of an X-linked Mendelian disorder located at Xp21?

Duchenne/Becker muscular dystrophy

In males with a balanced male X-autosome carrier, what is the consequence of spermatogenic arrest?

Invariably infertile

What genetic condition is associated with the XLIS gene located at Xq22.3?

Lissencephaly

What is the presumed mechanism of infertility in males with a balanced male X-autosome carrier?

Disruption of the sex vesicle

Why are unbalanced male X-autosome carriers with 46,Y,der(X),t(X;autosome) not viable?

Due to X nullisomy and autosomal trisomy

What are the common physical characteristics associated with Klinefelter syndrome?

Tall stature, tendency toward long arms and legs, small testes, gynaecomastia

Describe the phenotype of individuals with 47,XXX karyotype.

Mostly normal phenotype with normal fertility, IQ around 82, learning difficulties, and impaired language and speech.

What are the characteristics of individuals with 47,XYY karyotype?

Mostly normal phenotype with normal fertility, tall stature, IQ usually normal but lower than siblings, minor learning difficulties, and behavioral issues.

Which genetic conditions are associated with Xp21 and Xp22.3 deletions?

Xp21: Duchenne muscular dystrophy, Xp22.3: X-linked ichthyosis and hypogonadism

What are the characteristics of individuals with ring X syndrome?

Phenotype varies based on chromosome loss, can be associated with severe mental retardation due to X disomy.

Study Notes