the 47 , xxx karyotype ( triple x ) has a frequency of 1 in 1000 female newborns
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 can not yet be determined ; it is probably lower in the non - mosaic 47 , xxx patient than the mosaic 46 , xx/47 , xxx one .
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 .
karyotype 47 , xx + 21 of the daughter of triple x syndrome karyptype 47 , xx + x of the down syndrome 's mother
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 ) .
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 .
 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 can not 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
Case Report
Discussion