Deletion (13) (q14.1q14.3) in two generations: Variability of ocular manifestations and definition of the phenotype

Abstract

A 5-yr-old girl with unilateral retinoblastoma was found to have del(13)(q14.1q14.3). Her 16-month-old sister and 35-year-old mother, with retinal colobomata but without retinoblastoma, have the same deletion. Esterase D studies indicate reduced gene dose at this locus in the 3 females, consistent with a deletion of band 13q14. These patients are of apparently normal intelligence but have a mildly "coarse" facial appearance, a broad nasal bridge, upturned nares, and a long upper lip with thin upper lip vermillion similar to the phenotype suggested by Motegi et al [1983a] for patients with this deletion. Review of the literature documents 2 other patients with deletions of band 13q14 but without retinoblastoma, indicating that retinoblastoma is not a necessary consequence of this deletion. Of the 12 reported patients with deletions limited to band 13q14, seven had normal intelligence and five were macrocephalic. Insufficient clinical information is provided to draw conclusions about phenotype. The family which we describe and those reviewed by Motegi et al suggest that there may be a characteristic appearance in patients with this deletion.

Follow-up of retinoblastoma patients having prenatal and perinatal predictions for mutant gene carrier status using intragenic polymorphic probes from the RB1 gene

“…In both cases the referral for testing was warranted because of the presence of other congenital abnormalities and dysmorphology which are frequently associated with 13q14 deletions. Both patients eventually developed Rb, before 12 months, although it should be noted that not all such cases develop tumours Wilson et al, 1987).…”

Esterase D assay in Brazilian retinoblastoma families

“…According to the KnudsonlCavenee model, this would trigger the tumor, or alternatively, the tumor cells failed to pro- gress due to some unknown cause. In fact, the absence of retinoblastoma in individuals with low ESD activity has been reported previously [Pankau et al, 1987;Wilson et al, 1987;Cowell et al, 19881. 2. Another tenable hypothesis is that these relatives might have a null allele or ESDO.…”

Diagnosis of Cryptic Chromosomal Syndromes by Fluorescence In Situ Hybridization (FISH)

“…Sporadic cases of retinoblastoma have been reported in patients with mental retardation and interstitial deletions of the long arm of chromosome 13 (Francke, ). Some patients with visible deletions of band 13q14 may have retinoblastoma without mental retardation, while others may not have retinoblastoma (Wilson et al, ). Although the deletions can be of variable size, they appear to be visible with routine or high‐resolution cytogenetics in most cases.…”