Evaluation of Patients With Unresolved Chromosome Abnormalities

Inclusion Criteria

• •Physical anomalies or developmental anomalies.
• •Karyotype showing derivative chromosome abnormality that is not fully characterized.
• •No abnormal parental karyotype.
• •No prenatal specimens.
• •Probands of all ages, genders, and ethnic origin are eligible.
• •The proband must have a non-mosaic abnormal G-banded chromosome analysis of good quality that shows one or more derivative chromosomes whose foreign component cannot be determined by standard G-banding techniques.
• •The parents should also have G-banded chromosome analysis prior to eligibility for consent 2. If this has not been done by the referring physician, it may be done as part of the protocol.
• •The proband with the abnormal karyotype should have one or more of the following features: dysmorphic features; developmental delay or mental retardation; growth retardation, microephaly, short stature or failure to thrive; behavioral disorder
• •Biological parents must be willing to supply a blood specimen. If they have any of the features listed above, they must attend the clinic if the proband is to be eligible.
• •The proband must be evaluated by the NCHGR clinical genetics service by the PI, a co-investigator, or his associates.
• •Mothers will be queried about potential non-paternity. If non-paternity is possible, the family will need to undergo clinical paternity evaluation before they are enrolled in the study.