Numerical anomalies

The most common chromosomal disorder encountered is Down syndrome
(Trisomy 21). In this condition instead of the normal 46 chromosomes the affected people have 47 chromosomes and an additional chromosome 21 constitutes the excess chromosome. This condition usually occurs in babies born to elderly mothers especially women over 35 years. This is the most common form of Down syndrome, 90 - 95% (Non disjunction type). Younger couple can also have babies with Down syndrome. Hence it is highly imperative to check the karyotype of the baby to classify the type as around 5% of babies would be having translocation type of down syndrome where there is swapping of materials between two chromosomes and the parents of these babies should be karyotyped for detection of translocation in either of them which would be highly beneficial for the future counseling in next pregnancy. Mosaics constitute a small percentage of Down syndrome, where the patient has two sets of chromosomal patterns in their body, one normal and the other with Trisomy 21.

1. Turner syndrome
2. Klinefelter syndrome
3. Trisomy 13
4. Trisomy 18

1. Translocations
2. Inversions
3. Deletions
4. Duplications

1. Velocardiofacial syndrome Williams syndrome
2. Wolf Hirschhorn syndrome
3. Smith Meganis syndrome
4. 1p 36 deletion

Rare chromosomal disorders which were diagnosed in our department

Partial trisomy 9q in the patient with 9,17 balanced translocation in the mother
7p deletion
22q duplication with 11, 22 balanced translocation parent
Trisomy 13 mosiacism
8,18 translocation in the father and unbalanced 18q + in the baby
Translocation between chromosome 7 & X
XXX female
14/15 Robertsonian translocation in the mother

Delineation of several syndromes according to their clinical features is very important for counseling the parents regarding the future intervention programs and for the possible prenatal diagnosis in future pregnancies. Even though the list is exhaustive few common syndromic disorders are given below

1. Tuberous sclerosis
2. Neurofibromatosis Type I
3. Noonan syndrome
4. Fragile X syndrome
5. Cornelia de Lange syndrome
6. Prader willi syndrome
7. Syndromes with craniostenosis – Apert, Crouzon, Carpenter
8. Smith Lemli Opitz syndrome
9. Goldenhar syndrome
10. Ectodermal dysplasia
11. CHARGE association
12. VACTRAL anomaly
13. Marfan syndrome
14. Ellis Van Creveld syndrome
15. Kabuki make up syndrome
16. Russel Silver syndrome
17. Syndromes with associated deafness – Usher syndrome, Waardenberg, Pendred, Apert, Stickler syndrome
18. Neurocutaneous syndromes

Rare syndromes which were diagnosed in our department

Menkes kinky Hair syndrome who is being treated with parenteral copper histidinate which was specifically prepared for this patient in AIMS
Osteoporosis pseudoglioma syndrome
Carbonic anhydrase 2 deficiency
Micro syndrome
Malpuech syndrome
Gorlin Chowdhury Moss syndrome
Simpson Golabi Behmel syndrome
Johanson Blizzard syndrome
Rubinstein Taybi syndrome
Hypoglossia Hypodactyly syndrome
Costello syndrome
Fryns syndrome
Adams oliver syndrome
Mowat Wilson syndrome
Hajdu Cheney syndrome
Floating Harbour syndrome

This constitutes a group where the children have short stature associated with bony deformities. Characterization is very important as few types have specific therapies and is important for prenatal genetic counseling

1. Achondroplasia
2. Hypochondroplasia
3. Osteogenesis imperfecta
4. Metaphyseal dysplasias
5. Familial rickets
6. Spondyloepiphyseal dysplasia congenital

Rare skeletal dysplasias, which were diagnosed in our department

Spondylomegaepiphyseal metaphyseal dysplasia
Goldblatt syndrome
Geleophysic dysplasia
White Hemingway syndrome
Brachydactyly A4
Brachydactyly B

Children with neurodevelopmental delay or regression with visual or hearing impairment and physical bony deformities constitutes this group

1. Mucopolysaccharidosis _ Hurlur, Hunter, Morquio, Sanfilippo
2. Glycogen storage disorders
3. Niemann pick disease, Gaucher’s disease
4. GM1 gangliosidosis

This group encompasses the most important beneficiaries of the services of this department

• Previous baby with Down syndrome
• If either of a parent is a translocation carrier
• Previous baby with Neural tube defect
• Couple with children having mental retardation, storage disorders
• Previous baby affected with spinal muscular atrophy
• Elderly pregnant women, especially over 35 years
• Neuromuscular disorders in elder child eg- Duchenne muscular dystrophy
• Couple who are consanguineous and are carriers of enzyme defects- Thalassemia, sickle cell anemia, pyruvate kinase deficiency
• Couple with babies having inborn errors of metabolism
• Couple with children affected with neurodegnerative disorders
• Couple with history of recurrent miscarriages and those who have conceived following the treatment for infertility

1. Clinical diagnosis is offered to adult genetic disorders and the confirmation of diagnosis is offered with the help of mutation study of DNA sample for future management and counseling
2. Evaluation of primary amenorrhoea
3. Evaluation of couple with infertility
4. Couple with recurrent abortions for any chromosomal carrier state
5. Huntington’s chorea
6. Myotonic dystrophy
7. Ehlers Danlos syndrome

1. Metachromatic leukodystrophy
2. Sialidosis
3. Hallervorden Spatz syndrome
4. Ataxia Telangiectasia
5. Frederich’s Ataxia
6. Heriditary ataxias
7. Sandhoff disease
8. Tay Sach’s disease