Craniorachischisis in a Partially Trisomic 11 Fetus in a family with Reproductive Failure and a Reciprocal Translocation, t(6p+;11q-)

Abstract

Summary. A familial reciprocal translocation t(6p + ;l lq-) is presented, unbalanced (6p +) in the craniorachischisic propositus and balanced in his phenotypically normal father, associated with relative infertility, multiple spontaneous abortions, and failure to produce normal offspring. The karyotype-phenotype relationship is discussed with reference to other published cases of partial trisomy for the distal portion of the long arm of chromosome 11, and the concept of deletionunmasking is briefly considered. The occurrence of major neural groove closure defects due to a variety of translocations in mice is noted. The gametic segregation of balanced and unbalanced karyotypes is unique to each particular translocation making recurrence risk projections hazardous in the absence of prior experience with the particular translocation. The questions of the relative importance of genetic inheritance, chromosomal abnormalities, and many environmental factors including possible specific teratogens in causing neural groove closure anomalies are still unsettled. The paucity of published chromosome studies in these malformations is noted. We urge that cytogenetic studies with banding techniques be undertaken on these cases and their parents in order to expand basic knowledge of the role of chromosomal errors in their aetiology.Craniorachischisis, which combines anencephaly and total spina bifida with meningomyelocele, is the extreme example of defective neural groove closure. Because of their apparent anatomical and epidemiological similarity and the frequency with which one type may be born to a family which has already had another, defects such as craniorachischisis, anencephaly, spina bifida, meningomyelocele, and hydrocephalus are frequently considered together in attempts to elucidate their causes. Anencephaly is the most common and shows wide variation in incidence geographically and ethnically (Green, 1964), rang-

Congenital malformations associated with anencephaly and iniencephaly.

“…The exception would perhaps be the association of cleft palate; this probably is a simple developmental sequence that stems from the high position of the palatine raphe relative to the lateral palatine processes (Potter, 1961). It should be noted that anencephaly, with or without other malformations, can occasionally be associated with chromosome abnormalities, though exactly how frequent this is has not been established with the new banding techniques (Wright, Clark, and Breg, 1974;Schmid et al, 1975).…”

Balanced reciprocal translocations: risk factors for aneuploid segregant viability

“…In the LB group (210 cases from 202 families, Table 1) with cytogenetically documented abnormal probands, 147 couples cited by Jalbert et al (1980) were used. (Their cases from Wright et al (1974) and Kajii et al (1974) were included in our AB group.) In addition, 45 LB couples were collected from published reports and another 10 were from our laboratory.…”

Craniorachischisis Totalis: A Case Report and Review of the Literature

“…Grange et al [30] mentioned a craniorachischisis case associated with trisomy 18. Wright et al [31] reported a case of craniorachischisis in trisomy 11. Saraga-Babic et al [32] speculated that craniorachischisis is the result of primary affection of mesodermal structures during very early stages of development.…”