Prenatal diagnosis of a fetus with pure partial trisomy 1q32‐44 due to a familial balanced rearrangement

Abstract

We diagnosed a pure partial trisomy of the long arm of chromosome 1 in a fetus with multiple malformations detected prenatally. The father was a carrier of a balanced rearrangement involving 46,XY,inv(1)(qter-->p36::q32-->qter::p36-->q32). The fetus had preaxial polydactyly, low-set ears, macrocephaly, a prominent forehead, a broad and flat nasal bridge, a small mouth, an arched palate, micrognathia and unilateral renal agenesis. The couple had previously an infant with the same phenotypic abnormalities. The aberration was initially detected on amniocentesis with GTG banding and was confirmed by fluorescence in situ hybridization (FISH). Our case and other published pure trisomy 1q32-44 cases showed similarities, which allowed the further delineation of the trisomy 1q syndrome.

Attenuated phenotype in a child with trisomy for 1q due to unbalanced X;1 translocation [46,X,der(X),t(X;1)(q28;q32.1)]

“…The patients with pure trisomy for 1q32 ! qter show a fairly consistent pattern of congenital anomalies: severe pre-and postnatal growth retardation, macrocephaly, wide sutures and fontanelles, prominent forehead, triangular faces, broad and flat nasal bridge, midface hypoplasia, and visceral malformations, including urogenital and cardiac anomalies [Bartsch et al, 2001;Kimya et al, 2002;Nowaczyk et al, 2003]. There is, however, substantial phenotypic variability observed in patients with trisomy 1q and accompanying monosomy for another chromosomal region [Rasmussen et al, 1990;Johnson, 1991].…”

“…qter [Flatz and Fonatsch, 1979;Fryns et al, 1980;Clark et al, 1994;Duba et al, 1997;Kimya et al, 2002;Nowaczyk et al, 2003]. Numerator refers to the number of patients reported to have a given anomaly; denominator is the number of patients in whom this anomaly was investigated.…”

Partial 1q Duplications and Associated Phenotype

“…Distal 1q duplication syndrome is characterized by the signs present in almost all previously reported cases, namely intellectual disability/delayed neuropsychomotor development, a triangular face, slanted and narrow palpebral fissures, broad nasal bridge, pointed small nose, micrognathia, and low-set and posteriorly rotated ears with poorly formed helices ( table 1 ). Heart defects have been found in all patients (including patient 2) except for those reported by Lungarotti et al [1980] and Kimya et al [1979]. Though not described in all patients, cardiac defects are a common finding and, therefore, should be evaluated in patients with distal duplications of 1q.…”

“…In most cases, the duplication is the result of an unbalanced translocation with a possible imbalance of the other participating chromosome [Kimya et al, 1979;Concolino et al, 1998;Emberger et al, 2001;Percesepe et al, 2007;Utine et al, 2007]. It is difficult to evaluate the contribution of the 1q trisomy to the phenotype in cases involving another chromosome.…”

Equine clinical cytogenetics: the past and future

“…The homology of ECA30 extends in an inverted order from HSA1q31 ] q42. Human patients with partial trisomy 1 syndrome exhibit numerous congenital abnormalities which can include polydactyly (Kimya et al, 2002).…”