Triple X Egyptian woman and a Down's syndrome offspring.

The 47, XXX karyotype (triple X) has a frequency of 1 in 1000 female newborns. However, this karyotype is not usually suspected at birth or childhood. Female patients with a sex chromosome abnormality may be fertile. In patients with a 47, XXX cell line there appears to be an increased risk of a cytogenetically abnormal child but the extent of this risk cannot yet be determined; it is probably lower in the non-mosaic 47, XXX patient than the mosaic 46, XX/47, XXX one. We describe a new rare case of triple X woman and a Down's syndrome offspring. The patient is 26 years of age. She is a housewife, her height is 160 cm and weight is 68 kg and her physical features and mentality are normal. She has had one pregnancy at the age of 25 years resulted in a girl with Down's syndrome. The child had 47 chromosomes with trisomy 21 (47, XX, +21) Figure 1. The patient also has 47 chromosomes with a triple X karyotype (47, XX, +X) Figure 2. The patient's husband (27 years old) is physically and mentally normal. He has 46 chromosomes with a normal XY karyotype (46, XY). There are neither Consanguinity between her parent's nor she and her husband.

Introduction

The 47, XXX karyotype (triple X) has a frequency of 1 in 1000 female newborns. However, this karyotype is not usually suspected at birth or childhood.[1] Female patients with a sex chromosome abnormality may be fertile. In patients with a 47, XXX cell line there appears to be an increased risk of a cytogenetically abnormal child; however, the extent of this risk cannot yet be determined; it is probably lower in the non-mosaic 47, XXX patient than the mosaic 46, XX/47, XXX one.[2]

Case Report

The patient is 26 years of age. She is a housewife, her height is 160 cm and weight is 68 kg and her physical features and mentality are normal. She has had one pregnancy at the age of 25 years resulted in a girl with Down's syndrome. The child had 47 chromosomes with trisomy 21 (47, XX, +21) Figure 1. The patient also has 47 chromosomes with a triple X karyotype (47, XX, +X) Figure 2. The patient's husband (27-years-old) is physically and mentally normal. He has 46 chromosomes with a normal XY karyotype (46, XY). There are neither consanguinity between the patient's parents nor she and her husband.

Figure 1

Karyotype 47, XX + 21 of the daughter of Triple X syndrome

Figure 2

Karyptype 47, XX + X of the Down syndrome's mother

Discussion

The present triple X female was drawn to our attention after she gave birth to a child with Down's syndrome, where, there was nothing about this woman's physical appearance that would have indicated that she possessed an extra X chromosome. While many of the reported patients with the triple X syndrome have had reduced intelligence, this finding is probably due to a biased selection of patients (Day et al., 1964).[3] However, in (1972) Singer et al.[4] have reported a case with the same condition of our case. While many of the reported patients with the triple X syndrome have had reduced intelligence, this finding is probably due to a biased selection of patients (Day et al., 1964). Many of the initial reports about these females came from institutions for the mentally retarded where mass screening was performed. Our patient is one of the few observed with normal intelligence and this agrees with Singer's case.

To our knowledge, this is the first example of a triple X female giving birth to a child with Down syndrome in Egypt. It would be of interest to speculate that there is a causal relationship in the fact that this triple X mother produced a trisomy 21 child. If there is a cause and effect relationship between this triple X mother and the trisomic 21 offspring, it is difficult to propose a mechanism.[4]