Mosaicism for a chromosome 8‐derived minute marker chromosome in a patient with manifestations of trisomy 8 mosaicism

Abstract

We describe a patient with manifestations of the mosaic trisomy 8 syndrome and mosaicism for a minute marker chromosome. Fluorescence in situ hybridization (FISH) with a chromosome 8 probe confirmed that the marker was derived from chromosome 8. This is the smallest piece of chromosome 8 to be reported in a patient with mosaic trisomy 8 syndrome. When the clinical picture is strongly suggestive of trisomy for a specific chromosome region, we believe that FISH can be used to test markers in a guided, rather than random, fashion.

Familial transmission of a small supernumerary marker chromosome 8 identified by FISH: An update

“…Patients with a supernumerary marker of a small pericentric region of chromosome 8 have been reported previously [Melnyk and Dewald, 1994;Spinner et al, 1995;Butler et al, 1995]. These patients have a phenotype that is nonspecific but is described as consistent with that seen in patients with mosaic trisomy 8 syndrome.…”

Molecular cytogenetic characterization of a prenatally detected supernumerary minute marker chromosome 8

“…This is the third case described with such a minute SMC derived from the centromeric region of chromosome 8 {karyotype 47,XX,+der (8)(p11<q11)} and the first such case diagnosed prenatally (see Table 2). Spinner et al (1995) and Sasagawa et al (1995) described similar cases; however, the male patients showed clinical findings similar to mosaic trisomy 8. All other previous reports on chromosome 8 derived Plattner et al (1993) 3 (f) Ring Postnatally 40 Abnormal facial appearance, developmental delay at age 4 months Butler et al (1995) 4 (f) Ring Postnatally 40-72 Abnormal facial appearance, motor retardation, severe hearing defect at 1 year Blennow et al (1993) 5 (f) ?…”

“…This could be due to the fact, that in no previous study uniparental disomy for the two apparently normal chromosomes 8 was excluded (see Table 1), and might explain the fact that the presented case is clinically normal, in contrary to similar ones described by Spinner et al (1995) and Sasagawa et al (1995). Finally, the possibility, that the present case might be a familial one has been excluded by interphase FISH with a chromosome 8 specific alpha satellite probe (three signals per interphase nucleus have never been detected).…”

“…Postnatally 50 Mental retardation, abnormal facial appearance, skeletal abnormalies, clawing of the toes at the age of 7 years Daniel et al (1994) 7 (m) Ring Prenatally 54 Tallipes and overlapping toes at birth and developmental delay at age 3 months Hastings et al (1999) 8 (f) p11-q11 Prenatally 54 Normal at 9 months Present study 9 (m) p11-q11 Postnatally 56 Skeletal anomalies, developmental delay at 2 years Spinner et al (1995) 10 (f) Submetacentric Postnatally 97 Mild autistic behaviours and developmental delay at age 10 years and no anomalies at age 15 years Rothenmund et al (1997) 11 (f) Submetacentric Postnatally 98 Polydactyly at birth, developmental delay, autistic behaviours at age 10 years and no anomalies at age 17 years Rothenmund et al (1997) 12 (f) Ring Postnatally 100 Hypotonia, minor facial abnormalities, psychomotorich retardation at age 15 months Melnyk and Dewald (1994) 13 (f) Submetacentric Postnatally 100 Patent ductus arteriosus, developmental delay, mild dysmorphic features at age 2 years Ohashi et al (1994) 14 (m) ? Postnatally 100 Dysmorphic features and developmental delay (age?)…”

“…For the two other cases with a similar minute SMC (Spinner et al, 1995;Sasagawa et al, 1995) no information is available as to whether whole chromosome painting gave signals.…”