Males represented 54.13 % while females represented 45.87 % of the studied group. Table (3) shows the sex ratio in relation to cytogenetic data.

... Male (%) ... Female (%) ... Ratio

Non- disjunction ... 54.2 ... 45.8 ... 1.18

Translocation ... 63.9 ... 36.1 ... 1.7

Mosaic ... 45.5 ... 54.5 ... 0.8

Table (3): Sex ratio of the studied group

Maternal and paternal ages in relation to the cytogenetic data was are represented in tables 4, 5 and 6.

... Mean (years) ... Range (years)

Non - disjunction ... 31.8 ... 16 - 46

Translocation ... 24.5 ... 18 - 30

Mosaic ... 30 ... 20.5 - 39

Table (4): Mean maternal age in the studied group.

Age range (years) ... Non-disjunction (%) ... Translocation (%)

< 20 ... 3.57 ... 8.3

20 - 24 ... 14.28 ... 50

25 - 29 ... 20.24 ... 25

30 - 34 ... 21.13 ... 16.6

35 - 39 ... 26.49 ... 0

40 - 45 ... 13.99 ... 0

>45 ... 1 ... 0

Table (5): Maternal age range in non-disjunction and translocation cases.

... Mean (years) ... Range (years)

Trisomy 21 ... 36.93 ... 19 - 62

Translocation ... 30.6 ... 24 - 35

Table (6): Paternal age of the studied group

Family history of previously affected sib was positive in 3.18 % of cases and in close relative in 2.82% of cases. Family history of mentally retarded sib or close family member was found in 3.6% of cases. Most of the cases were first or second order of birth. Table 7 and 8 show referral causes in postnatally and prenatally referred cases.

Indication: ... ... Percentage

Dysmorphic features ... 72.05

Mental retardation ... 12.15

Delayed physical milestones ... 7.9

Hypotonia ... 1.3

Congenital heart disease ... 1.65