Frequency of somatic and germ-line mosaicism in retinoblastoma: implications for genetic counseling

Article Abstract:

Frequency of somatic and germ-line mosaicism has been studied in retinoblastoma and implications for genetic counseling have been considered. An evaluation has been made of 156 families with retinoblastoma. In these families the initial oncogenic mutations in the retinoblastoma gene had been found. In about 10% of the families mosaicism for the initial mutation in the retinoblastoma gene was documented in the proband or in one of the parents of the proband. Germ-line DNA from two mosaic fathers was analyzed. Data suggest that mosaicism is more common that generally believed especially in disorders like retinoblastoma in which a high proportion of cases come from new mutations. The possibility of mosaicism should be considered in genetic counseling of newly identified retinoblastoma families. Genetic tests of germ-line DNA can give valuable information not found in analysis of somatic, leukocyte, DNA.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code:

Characterization of a germline mosaicism in families with Lowe syndrome, and identification of seven novel mutations in the OCRL1 gene

Article Abstract:

A germline mosaicism in families with Lowe syndrome has been characterized, and seven novel mutations in the OCRL1 (ital) gene identified. The oculocerebrorenal syndrome of Low (OCRL) is X-linked and characterized by major abnormalities of kidneys, eyes, and the nervous system and associated with mutations in the OCRL1 gene. This gene has been studied in eight unrelated OCRL patients. Two nonsense mutations and three frameshift mutations brought on premature termination of the protein. Two microsatellite markers were found for the OCRL1 locus and a germline mosaicism was seen in one family. Genetic counseling implications exist.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code:

Absence of linkage of phonological coding dyslexia to chromosome 6p23-p21.3 in a large family data set

Article Abstract:

The absence of linkage to chromosome 6p23-p21.3 for phonological coding dyslexia (PCD) in a large family data set is discussed with data from an investigation of 79 families with two or more siblings affected by phonological coding dyslexia. Use of the affected-pedigree-member (APM) method should be undertaken with caution since false-positive results seem to have been generated in other studies.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code: