Partial 6p Trisomy with Abnormal ABR and Hypogenesis of the Corpus Callosum.

Abstract

A case of 4-month-old male infant with the karyotype 46,XY,-21, +der(21), t(6;21)(p22; p13) mat is reported. His cranial magnetic resonance imaging (MRI) suggested hypoplastic corpus callosum and auditory brain stem response (ABR) revealed brain stem dysfunction. Partial 6p trisomy is characterized by a low birth weight, psychomotor retardation and dysmorphic craniofacial features. We report mainly the neurologic findings, including MRI and ABR results of a 4-month-old male infant with 6p trisomy. CASE REPORTThe patient was the parent's second child. An elder brother aged 4 years was healthy. The mother and father were consanguineous. The father's maternal grandmother was a cousin of the mother's maternal grandmother. The father and mother were 34 and 32 years of age. Both parents were healthy. The father had one sibling with cerebral palsy, and the mother had one healthy sibling. The maternal grandmother had a history of spontaneous abortion. The patient was delivered by cesarean section at 37 weeks of gestation because of intrauterine growth retardation. At birth, he weighed 1,498 g, and was considered small for his gestational age. His length and head circumference were 40.0 cm and 28.4 cm, respectively. He required mechanical ventilation because of respiratory failure after neonatal asphixia for 6 days, and phototherapy to jaundice for 5 days. Craniofacial features included: microcephaly, a broad forehead, a large anterior

Pure 6p22‐pter trisomic patient: Refined FISH characterization and genotype‐phenotype correlation

“…Of these patients, one was a case of direct inheritance from an only mildly affected father [Delatycki et al, 1999], 31 were the unbalanced progeny of a parent with a balanced rearrangement [Wauters et al, 1993;Nakajima et al, 1995;Song and Li, 1996;Rothlisberger et al, 1999] and only ten were de novo cases [Villa et al, 2000].…”

“…Of the 42 previously reported patients with partial trisomy 6p, 28 involved inheritance from a parental balanced translocation [Fryns et al, 1983;Katafuchi et al, 1992;Wauters et al, 1993;Nakajima et al, 1995;Song and Li, 1996;Rothlisberger et al, 1999], three from a pericentric inversion [Wauters et al, 1993], ten were de novo [Turleau et al, 1978;Muneer et al, 1984;Eden et al, 1985;Burd et al, 1988;Chaveau et al, 1988;Wauters et al, 1993;Rudnik-Schoneborn et al, 1996;Delatycki et al, 1999;Villa et al, 2000], and one was directly inherited from an unbalanced parent [Delatycki et al, 1999]. The proximal breakpoint varied from p11 to p25 [Lytle et al, 1986;Scarbrough et al, 1986].…”

De novo ?pure? partial trisomy (6)(p22.1?pter) in a chromosome 15 with an enlarged satellite, identified by microdissection

“…Once the extra material on the aberrant chromosome 15 was identified as originating from the short arm of chromosome 6, we searched for literature‐reports on trisomy of various regions of 6p. The unbalanced inheritance of a parental translocation caused partial trisomy 6p in 31 cases [Therkelson et al, 1971; Gouw et al, 1973; Chiyo et al, 1975; Breuning et al, 1977; Cote et al, 1978; Turleau et al, 1978; Bernheim et al, 1979; Rosi et al, 1979; Pagano et al, 1980; Yuksel et al, 1980; Ferrando et al, 1981; Fryns et al, 1983, 1986; Muneer et al, 1984; Smith and Petterson, 1985; Scarbrough et al, 1986; Burd et al, 1988; Krassikoff and Sekhon, 1989; Lytle et al, 1989; Katafuchi et al, 1992; Nakajima et al, 1995; Song and Li, 1996; Delatycki et al, 1999; Rothlisberger et al, 1999]. The clinical picture of these patients was influenced by the accompanying monosomy of different chromosome regions.…”

Unbalanced 4;6 translocation and progressive renal disease

“…The short arm of chromosome 6 may [Therkelsen et al, 1971;Chiyo et al, 1975;Breuning et al, 1977;Bernheim et al, 1979;Pearson et al, 1979;Pagano et al, 1980;Muneer et al, 1984;Smith and Pettersen, 1985;Eden et al, 1985;Chauveau et al, 1988;Katafuchi et al, 1992;Rudnik-Schöneborn et al, 1997]. b [Gouw et al, 1973;Côté et al;Turleau et al, 1978;Rosi et al, 1979;Yü ksel et al, 1980;Ferrando et al, 1981;Fryns et al, 1983;Muneer et al, 1984;Burd et al, 1988;Wauters et al, 1993;Nakajima et al, 1995;Song and Li, 1996;Delatycki et al, 1999;Röthlisberger et al, 1999].…”