Inherited interstitial del(Xp) with minimal clinical consequences: With a note on the location of genes controlling phenotypic features

Abstract

In a routine cytogenetic investigation of the outpatients of a hospital for the mentally retarded, a 26-year-old women with a presumptive interstitial deletion of the short arm of one of the X chromosomes was found. The same aberration was found in her phenotypically normal mother and in one of her four sisters, all phenotypically normal. By GTG- and QFQ-banding methods, the deletion was interpreted to involve the entire band Xp21 and adjacent parts of p11 and p22. The karyotype is written 46,X,del(X)(pter leads to p22::p11 leads to qter). By autoradiography and Bud R acridine orange technique, the deleted X was the late replicating one in all three affected persons. The deletion apparently causes shortness of stature but no other phenotypic symptoms or signs. Hence a gene or genes controlling stature is located in band Xp21 or regions immediately adjacent to this band. Since the absence of this region does not cause streak gonads, it does not contain genes controlling the formation of the ovaries. This appears to be the first example of a heritable chromosome deletion compatible with a normal phenotype and reproduction.

Transmission of Del(X)(p11.2) from Mother to Daughter.

“…Hoo (27) suggested that deletions distal to p11 are asymptomatic. This suggestion was supported by Herva et al (25). However, Goldman et al (26), noted that only the size of the deletion in an X chromosome cannot predict whether a Turner patient menstruated or not.…”

“…The karyotype of the 1st pair was del(X)(p211) and the second had del(X)(p114). A woman with del(Xp), who marries a normal man, may have a daughter with the same karyotype (with a probability of one in three) but not a son because a combination of Y and del (Xp) is fatal (25). In some families, mothers with 45,X/ 46,X,del(X) gave birth to daughters with a single cell line of del(Xp) (21,24).…”

“…In these families, the deleted X chromosome was del(X)(p21.2) in one (21) and del(X)(p21.1) in another family (24). Furthermore, some familial Turner cases have been described in which the deleted part of the X chromosome was translocated to an autosomal chromosome (15,25). Hoo (27) suggested that deletions distal to p11 are asymptomatic.…”

Diagnostyka rearanżacji genu SHOX u kobiet 46,XX z idiopatyczną niskorosłością

“…In female patients affected by the above-  mentioned rearrangement, no normal pubertal spurt is observed. The presence of certain small morphological abnormalities plus subtle radiological symptoms are significant markers, indicating the necessity of genetic studies [2][3][4][5].…”

Mapping of the X-linked agammaglobulinemia locus by use of restriction fragment-length polymorphism.

“…After transfer, the filters were rinsed in 4X SSC, and baked for 2 h at 80'C. Prehybridization was performed in a mixture containing 50% formamide, 4X SSC, 8% dextran sulfate, lOx Denhardt's solution (15), 25 gg/ml denatured salmon DNA, 100 jsg/ml transfer RNA (tRNA), 1 (28,29). One of these females had decreased T helper lymphocytes but normal numbers ofB cells.…”