Editor—We report on a case with an apparent duplication of 22q with an initial karyotype of 46,XY,add(6)(p24).ish der(6)(6qter→6p24::22q11→22qter)(wcp6+,wcp22+). To our knowledge this is the first report of such an association. We have attempted to characterise the exact regions of duplication using fluorescence in situ hybridisation (FISH) techniques and confirmed that the case is indeed not deleted for chromosome 6 and is only partially trisomic for 22q, thus allowing a more detailed genotype-phenotype correlation than previous studies.

The majority of reports of duplication of chromosome 22 involve the proximal region on 22q. The most common cause of trisomy or tetrasomy of proximal 22q is a de novo supernumerary bisatellited marker chromosome derived from inverted duplication of 22p and 22q11. These supernumerary marker chromosomes have been associated with the cat eye syndrome (CES).1 In contrast, duplications of the distal part of the chromosome 22q region that arise de novo are relatively rare with only eight cases reported so far.2-9 A clinical picture of the distal 22q duplication syndrome has emerged from this limited number of cases comprising growth retardation, shortened life span, congenital heart defects, hypertelorism, narrow palpebral fissures, small nose with anteverted nares, small thorax with hypoplastic nipples, muscular hypotonia, feeding difficulties associated with failure to thrive, and anomalies of the external genitalia in males.5 9

The boy was born at 39 weeks after an uneventful pregnancy to healthy, non-consanguineous, 33 year old parents. It was the second pregnancy; the first pregnancy was spontaneously aborted at 6 weeks' gestation. Family history was normal. Clinical examination at birth showed a proportionately small infant; weight was 1500 g (−4.5 SD), length 39 cm (−5.9 SD), head circumference (OFC) 28.3 cm (−3.7 SD), and chest circumference 25.3 cm (−4.1 SD). He had cyanosis because of persistent fetal circulation, but …