Gene knock-outs

Gene knock-ins

Gene overexpression

Conditional knock-outs

LINE

Copy-number variations

Segmental duplications

Pseudogenes

He will almost certainly develop Alzheimer disease.

He is protected from Alzheimer disease.

He is at increased risk of Alzheimer disease.

This result has no bearing on his risk of Alzheimer disease.

The trait has no genetic component.

The trait is completely determined by genetics.

Genes contribute to the trait, but are not deterministic.

The trait must be due to the biology of twinning.

1000

100

10

1

They are not at increased risk due to the absence of prior family history.

They are only at increased risk if they are related to one another.

They are only at increased risk if the next child is of the same sex as the previously affected child.

They are at increased risk, which can be estimated from empirical data.

stimulation of lymphocyte cell division

chromosome condensation

collection of large number of cells at metaphase

swelling of cells to permit chromosome visualization

Cowden syndrome

Li-Fraumeni syndrome

Williams syndrome

Angelman syndrome

47, XXX

47, XYY

47, XXY

45, X

trisomy 13

trisomy 18

trisomy 21

trisomy 15

Velo-cardio-facial syndrome

Fragile X syndrome

Rett syndrome

Bloom syndrome

Thrombophilias

Hemophilias

Ataxia-telangiectasia

Hemoglobinopathies

Acute intermittent porphyria

Leber hereditary optic neuropathy

Lesch-Nyhan syndrome

Homocystinuria

Red-Green colour blindness

Hereditary deafness

Tyrosinemia

Galactosemia

Cell membrane receptor

Transcription factor

DNA mismatch repair

Cell cycle control

hereditary nonpolyposis colon cancer

familial adenomatous polyposis

hereditary breast cancer

Neurofibromatosis

EGF receptor gene

NF1 gene

Myc oncogene

ABL gene

This is a normal variant, likely of no significance.

This is an abnormal chromosome that would cause congenital anomalies if transmitted to the developing foetus.

This rearrangement might cause chromosomal imbalance in developing foetus and could explain multiple miscarriages.

This rearrangement might cause dicentric or acentric chromosomes in developing foetus, which would probably not be compatible with survival of the developing foetus.

The chromosome study should be repeated in another laboratory.

A normal karyotype rules out all detectable chromosomal abnormalities.

The boy should have FISH analysis for all known microdeletions.

Analysis for subtelomere deletion may detect an abnormality missed by convential chromosomal analysis.

Down syndrome is generally infrequent, so there is no increased risk to this couple.

If her sister's karyotype analysis cannot be done, the woman herself should have chromosomal analysis.

The pregnancy of the woman will be screened in the second trimester using alphafetoprotein, bhCG, and unconjugated estriol, which will be sufficient to detect Down syndrome, if it has occurred.

The couple should obtain prenatal diagnosis by chorionic villus sampling or amniocentesis.

The fetus likely has trisomy 15, and maternal cell contamination probably explains the normal amniocensis.

The fetus will likely be normal, and confined placental mosaicism probably explains the abnormal CVS result.

The fetus should be tested uniparental disomy of chromosome 15, given the risk of Prader -Willi or Angelman syndromes.

The abnormal CVS is probably due to pseudomosaicism and the fetus is likely to be normal.

The child will be a carrier.

The child will be affected if recombination takes place in the father only.

The child will be homozygous unaffected if recombination takes place in the mother.

All of the above

the likelihood that a mutation stated to be present is in fact present

the likelihood that identification of a mutation correctly predicts presence or absence of disease

the likelihood that a mutation test will successfully identify a pathogenic mutation

the likelihood that an identified mutation is pathogenic vs. a benign variant

Missense mutation

Nonsense mutation

Deletion of an exon

Inversion of part of the gene

Test both parents to see if the mutation is found only in the child.

Determine whether the mutation affects an amino acid that is conserved in evolution.

Examine the structure of the protein to see if the mutation has a major effect on protein function or not.

Review the literature to see if the mutation has been reported to be pathogenic.