The critical monosomic segment involved in 4p- syndrome: A high-resolution banding study on five inherited cases

Abstract

SummaryIn an attempt to determine the critical monosomic segment involved in 4p-syndrome, we studied the precise breakpoints of five inherited cases with the syndrome using a high-resolution banding technique. The 5 patients ranged in age at diagnosis from newborn to 15 months, 4 of whom could be clinically diagnosed as having 4p-syndrome. Common clinical features included mental retardation, low birth weight, growth failure, hypotonia, microcephaly, peculiar facial dysmorphia and ear malformations. Karyotypes of the 5 were 46,XX,-4, +der(4),t(4;21) (p16.1 ;q22.3)pat; 46,XX,-4,+der(4), inv ins(4;9)(p15.32p16.3;q34.3)pat; 46,XX, rec(4),del p,inv(4)(p15.2q35)pat; and 46,XX,-4, + der(4),t(4;18) (pl5.2;pll.21)mat (two cases, related). The results suggested that monosomy for the proximal half of the 4p16 band is sufficient to express 4p-syndrome.

Effect of the size of the deletion and clinical manifestation in Wolf-Hirschhorn syndrome: analysis of 13 patients with a de novo deletion

“…3,10 The rate of familial translocations in WHS patients has been reported to be up to 15%, 10 66% of them maternally inherited. 11 De novo events are estimated to occur in 85-87% of WHS patients 10 and here the paternally derived deletions are more frequent. 12,13 Here, we evaluate 13 WHS patients with de novo deletions by clinical, cytogenetic, and molecular analyses to assess the severity of the clinical phenotype in context of the size and origin of the deletion.…”

Recombinant chromosome 4 resulting from a maternal pericentric inversion in two sisters presenting consistent dysmorphic features

“…The chromosome 4 inversion [inv (4)] with breakpoints p13-p15q35 results in a recombinant 4 chromosome [rec (4)] with partial 4p duplication [dup(4p)]/4q deletion in approximately 80% of the carriers' offspring [3]. Whether the recombinant 4p syndrome can be recognized as a clinical entity, however, is still a topic open to controversy [5,6]. In the opinion of many authors, the rec(4)dup(4p) phenotype is not specific because the spectrum of rec(4)dup(4p) phenotypes might reflect not only the variable sizes of the 4p duplication and 4q deletions but also molecular differences resulting from the different location of the break points within the chromosome [5].…”

Greek Warrior Helmet Facies (Wolf-hirschhorn Syndrome)

“…A familial transloca on is responsible for only 5 -13 % of cases 13 . WHS is mostly maternally inherited with a 2:1 ra o female to males 14 .…”