Academic journal article Genetic Counseling

CLINICAL DELINEATION OF A PATIENT WITH TRISOMY 1q32-Qter AND MONOSOMY 5p RESULTING FROM A FAMILIAL TRANSLOCATION 1;5

Academic journal article Genetic Counseling

CLINICAL DELINEATION OF A PATIENT WITH TRISOMY 1q32-Qter AND MONOSOMY 5p RESULTING FROM A FAMILIAL TRANSLOCATION 1;5

Article excerpt

Summary: Clinical delineation of a palien! with trisomy 1q32-qtcr und monosoiny Sp resulting from a familial translocation 1:5: We describe a patient who had multiple malformations including veiilrieuloniegaly, colpocephaly, corpus callosum, cerebellum and vermix hypoplasia, optic nerve hypoplasia, corneal opacity and congenital heart disease in whom a trisomy 1q32-qter and monosomy 5p derived from a t(1 ;5)mat was diagnosed by karyotype and FISH analysis. This trisomy/monosomy association has not been previously reported. The familial analysis of the IransJocation was carried oui in four generations and ils implicalions on Ine phenolype of the patient and genetic counseling are discussed.

Key-words: Trisomy - Monosoiny - Cri du chat Syndrome - Chromosomal translocation.

INTRODUCTION

An abnormal chromosome analysis has been reported in up to 50% of spontaneous miscarriages, 6% of stillbirths and in 0.5% of newborns. Among the best characterized chromosome syndromes at the newborn stage is the Cri-du chat syndrome (CDCS), affecting 1 :15 000 to 1:50 000 live births. CDCS results from a partial deletion ranging from 5 to 40 Mb of the short arm of chromosome 5 (22). The main clinical characteristics of CDCS are low weight at birth, microcephaly, neonatal hypotonia, round face, downward slanting palpebral fissures, hypertelorism, broad nasal bridge, epicanthal folds, micrognathia, downturned corners of the mouth, low-set ears, abnormal dermatoglyphics and a typical catlike cry. The psychomotor retardation is evident from the first year of age and cardiac and cerebral malformations can also occur (14, 24). It has been considered that 3.75%- 10% of CDCS (II, 14) cases result from a familial translocation. A given phenotype may be modified by the extension of the deletion and the influence of the genetic background. Moreover, in a minor set of patients, a rearrangement that involves a critical region may mainly cause a karyotype -phenotype effect of the trisomy over the monosomy, and vice versa (3, 7, 1 5).

Partial trisomy 1 q syndrome (PTl qS) is an infrequently reported chromosome abnormality which has been described either isolated or accompanied by other chromosome aberrations such as monosomy. The clinical characteristics associated to trisomy Iq syndrome are low weight at birth, large fontanelles, prominent forehead, downward slanting palpebrai fissures, broad nasal bridge, facial nevi, low-set, rotated ears, hands and feet abnormalities and psychomotor retardation (4). PTIqS cases more frequently involve regions Iq32-qter or Iq42-qter. Therefore, it has been suggested to categorize the PTIqS cases accordingly, as so far only the proximal form has been associated with severe heart disease and urogenital abnormalities (5).

Here we describe a patient who had multiple malformations and in whom a trisomy 1 q32-qter and monosomy 5p derived from a t( 1 ;5)mat was diagnosed, a trisomy/monosomy association not previously reported. The familial analysis of the translocation, its implications on the phenotype of the patient and the genetic counseling are discussed.

CLINICAL REPORT

The proband was a female product of the third pregnancy of non-consanguineous, young, healthy parents. There had been a previous miscarriage and an older healthy girl. A maternal aunt had two unexplained perinatal losses apparently associated to hydrocephaly. Both products died a few hours after birth and were not evaluated in our hospital (Fig. 1). The proband's pregnancy was uneventful with adequate medical care and ultrasound studies were reported as normal. The mother smoked during the first trimester. The baby was delivered at 36.4 weeks by iterative cesarean section. Birth weight was 230Og (

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.