MOSAIC FORMS IN DOWN’S SYNDROME:

A SURVEY ON SIXTEEN CASES

 

Renato COCCHI, a neurologist and a medical psychologist


Abstract

Sixteen mosaic Down syndrome subjects ( F= 5 and M = 11; age at first consultation: 11-228 months, average 107.56) had symptoms analysis to determine if they differ from other DS chromosomal forms. Symptoms or behaviours checked were: delivery and its troubles; food habits, in particular for sweet things and broth and refusal to have breakfast before 9-10 AM; sleep habits and strange postures during sleep; toilet habits; heart anomalies and squint; age at autonomous walking, motor skills, hypotonia , tongue protrusion, hyperkinesis; symptoms of stress or compensatory symptoms (depression or irritability , easiness to respiratory tract infections, bruxism, mouth stimulation, masturbation; other somatic symptoms (a low threshold for hot or cold, abnormal sweating, paleness)eight and weight; language development, socialisation, school achievement, Pervasive Developmental Disorders, typical Down physical features (look).

In this sample it is not possible to find some overall superiority in comparison with other DS forms, but the large extent of peri- and neo-natal troubles could have modified the outcomes.

Key words: Down syndrome, mosaicism, symptoms analysis, physical features.

Italian translation 

Down's syndrome

Mental retardation

Symptoms

Home Page

 

Mosaic anomaly among Down's syndrome anomalies stands out in many ways. It is quite rare, by ranging 2-4%, a fact coupling mosaic forms to translocations. Though it is asserted as the only one having its starting point after the conception, being both translocations and pure trisomy 21 gametes' anomalies. Moreover it is the only one that can vary in the rate of trisomic cells.

For these reasons mosaicisms have raised some "logical statements," the main of which is that these forms are less typical Down than the other Down's syndrome's anomalies. The evidence does not always support this view, and many researchers inclined to find new but hardly exaustive variables.

Since these variables did not wholly suffice, then somebodies claimed for a "paradox" instead of getting at a different explanation. The so-called paradox of the mosaicism comes out from the fact that some pure trisomic children look less typically Down than sure mosaic DS children.

This is true and the explanation does not pertain to a possible mistake in chromosome mapping. In other terms, by having a third chromosome 21 in all cells can lead to less "typical" Down features than by having it only in a share of them.

As an attempt to sum up this problem, I decided to do a survey on a sample of mosaic forms from a cohort of 533 Down's syndrome subjects.

Materials and method.

I checked the records of all Down syndrome subjects I saw at first consultation

from January 1979 to May 1966, and I singled out mosaic forms.

From these I collected sex, the year of birth, the age at first consultation, maternal age at birth. Other symptoms or behaviours checked were:

- delivery and its troubles (Cocchi and Branchesi, 1986).

- food habits (Cocchi, 1995) (in particular for sweet things and broth ( Ward, Thanki and Bradford, 1983; Cocchi 1990)) and refusal to have breakfast before 9-10 AM;

- sleep habits and strange postures during sleep (Cocchi, 1989);

- toilet habits (Cocchi 1996);

- heart anomalies (Cocchi, 1990) and squint ( Cocchi and Branchesi, 1986, Cocchi 1991);

- age at autonomous walking (Cocchi, 1989), motor skills (Felicioli and Moretti 1984), hypotonia (Favuto and Cocchi, 1992), tongue protrusion, hyperkinesis;

- symptoms of stress or compensatory symptoms (depression or irritability (Szymanski and Biederman, 1984; Cocchi 1994), easiness to respiratory infections (Cocchi 1981, 1987, 1990), bruxism ( Morse, 1982; Cocchi and Lamma, 1987; Lamma and Cocchi 1988)), mouth stimulation (Cocchi and Tornati, 1976) , masturbation (Cocchi and Ghiglione Rocca, 1977)

- other somatic symptoms (a low threshold for hot or cold (Cocchi, 1989), abnormal sweating, paleness), eight and weight (Cercolani 1988, 1989);

- language development (Felicioli and Moretti, 1984), socialisation, school achievement (Cocchi 1992), Pervasive Developmental Disorders (Cocchi, 1989), typical Down features (look). Data were only processed in plain statistics.

Results

Only 16 records out of 533 (3%) pertained to subjects having mosaicisms. Data collected are shown in tables 1-10.

Table 1: Epidemiological data

S

Sex

Year of birth

Age at 1st

visit (months)

Mother's age at delivery (years)

 

 

 

1

f

1986

11

36

2

f

1974

133

33

3

f

1981

57

41

4

f

1979

67

31

5

f

1978

102

28

6

m

1976

133

22

7

m

1973

116

37

8

m

1971

228

26

9

m

1977

110

37

10

m

1977

61

30

11

m

1973

134

38

12

m

1979

108

38

13

m

1984

13

38

14

m

1976

175

39

15

m

1975

179

39

16

m

1978

94

28

Average

 

 

107.56

33.75

 

Table 2: Birth troubles

S

Time:

(40 weeks)

Weight

at birth (g)

Delivery

troubles

Cyanosis or asphyxia

Respirat.

distress

Hyper bilirubinemia

 

1

-4

2680

Caesar. section

 

yes

 

2

0

2360

Umbilical cord

yes

 

 

 

 

 

around the neck

 

 

 

3

0

3150

Caesar. section

yes

yes

 

4

0

2700

 

 

 

yes

5

0

2850

 

yes

yes

 

6

0

2980

 

yes

yes

 

7

-4

3000

Long lasting

 

 

yes

8

0

3600

 

yes

yes

 

9

0

3500

 

 

 

yes

10

0

3700

Short lasting

yes

 

yes

11

0

3700

Dry delivery

 

 

 

12

0

2600

 

 

 

yes

13

0

4200

Induced by drugs

yes

yes

 

14

0

3850

Caesar. sect.

 

 

 

15

0

4020

Induced by drugs

yes

 

yes

16

0

3200

Dizygotic twins

 

 

 

 

To be noted: Only two premature babies, only one low weight at birth, but increased delivery troubles and peri- and neo-natal risk factors.

 

Table 3: Food habits with particular reference to sweet things and broth, and refusal to have breakfast.

S

F o o d

Sweets

Broth

Breakfast

refusal

 

preference

refusal

 

 

1

unknown

unknown

refusal

unknown

no

2

no

no

scarce

unknown

yes

3

no

all vegetables

normal

increased

no

4

no

raw vegetables

scarce

normal

no

5

no

no

Increased

increased

yes

6

bread

all vegetables

scarce

increased

no

7

no

no

scarce

unknown

no

8

no

no

scarce

normal

no

9

no

no

Increased

normal

no

10

no

milk & all veget.

scarce

normal

yes

11

no

all vegetables

normal

increased

no

12

no

no

Increased

normal

no

13

milk

no

Increased

unknown

no

14

no

all vegetables

Increased

reduced

no

15

milk

all vegetables

scarce

increased

no

16

no

no

normal

normal

no

To be noted in Table 3: Two increased preferences for milk, one refusal for milk; seven refusals for vegetables; eight refusals or scarce liking for sweets, but eleven normal or increased liking for broth; three refusals to have breakfast before 9-10 AM.

Table 4 : Sleep habits, and strange postures during sleep.

S

normal

Difficulty in

falling asleep

pavor

nocturnus

Type 1 sleep

posture

Type 3 sleep

posture

 

 

1

 

yes

 

 

 

2

 

yes

 

 

 

3

yes

 

 

 

 

4

yes

 

 

 

 

5

yes

 

 

yes

 

6

yes

 

 

 

 

7

yes

 

 

 

 

8

yes

 

 

 

yes

9

yes

 

 

yes

 

10

yes

 

 

 

 

11

yes

 

 

yes

 

12

 

yes

 

 

 

13

 

 

yes

 

 

14

yes

 

 

 

 

15

yes

 

 

yes

 

16

Yes

 

 

 

 

To be noted: Only three difficulties in falling asleep, one pavor nocturnus, but five strange postures during sleep.

 

Table 5: toilet habits

 

Habit x S

Subject's number

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Not checked

 

 

 

 

 

 

 

 

 

*

*

*

 

 

*

 

Normal

*

*

*

*

 

*

*

 

 

 

 

 

*

*

 

 

Atonic const.

 

 

 

 

*!

 

 

*

*

 

 

 

 

 

 

 

Spastic const.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*

Diarrheas

 

 

 

*$

 

 

*$

 

 

 

 

 

 

 

 

 

! = very atonic; $ = rare

To be noted: Only three Ss with atonic constipation, and only one with spastic constipation.

 

Table 6: Heart defect, open surgery correction, and convergent squint.

S

Heart defect

Open heart

Days in IC

Squint

 

 

surgery

 

 

1

Not reported

yes

5

no

2

no

 

 

no

3

no

 

 

yes

4

VSD

no

 

yes

5

no

 

 

no

6

no

 

 

yes

7

no

 

 

no

8

no

 

 

yes

9

Not reported

yes

10

yes

11

no

 

 

yes*

12

no

 

 

no

13

Not reported

yes

8

no

14

no

 

 

yes**

15

no

 

 

yes

16

no

 

 

yes

(*) alternate squint (**) partially corrected by surgery

To be noted: heart defects in 25% and squint in more than 56% (increased).

 

Table 7: autonomous walking, motor skills, hypotony, tongue protrusion and

hyperkinesis.

S

Age at walking

Motor

Hypotony /

Tongue

Hyper-

 

(months)

skills

joint laxity

protrusion

kinesis

1

Not acquired*

normal

yes

yes

yes

2

Unknown

Clumsiness

yes

open mouth

no

3

24

normal

no

no

no