Image Based Question-65824

An 8 month old boy presents with recurrent respiratory tract infection and pale coloured and oily stools.His elder brother is also suffering from same problem. The X-ray findings of his lungs are shown in the picture below. He is diagnosed to be suffering from an Autosomal recessive disease.The mutation in this condition is on which chromosome?

A. 7p.

B. 7q.

C. 5p.

D. 5q.

Correct Answer » B Explanation

The mutation in cystic fibrosis is on 7q chromosome.

The patient in question is suffering from Cystic Fibrosis.

Cystic fibrosis

• It is an autosomal recessive disease caused by defects in the CFTR gene, which encodes for a protein that functions as a chloride channel, and also regulates the flow of other ions across the apical surface of epithelial cells.
• CF locus lies on the long arm of human chromosome 7, band q31.

Median age at diagnosis is 6-8 months.

• Patients younger than 1 year may present with wheezing, coughing, and/or recurring respiratory infections and pneumonia.
• GI tract presentation in early infancy may be in the form of steatorrhea, failure to thrive, or both.

Requirements for a CF diagnosis include either positive genetic testing or positive sweat chloride test findings (>60 mEq/L) and 1 of the following:

• Typical chronic obstructive pulmonary disease
• Documented exocrine pancreatic insufficiency
• Positive family history (usually affected sibling).
• On chest radiography, initial changes are hyperinflation and peribronchial thickening.
  •  Progressive air trapping with bronchiectasis may be apparent in the upper lobes. With advancing pulmonary disease, the following findings may be noted:
  • Pulmonary nodules resulting from abscesses
  • Infiltrates with or without lobar atelectasis
  • Marked hyperinflation with flattened domes of the diaphragm

Medications used to treat patients with cystic fibrosis may include the following:

• Pancreatic enzyme supplements
• Multivitamins (including fat-soluble vitamins)
• Mucolytics
• Nebulized, inhaled, oral, or intravenous antibiotics
• Bronchodilators
• Agents devised to potentially reverse the abnormalities in chloride transport (eg, ivacaftor , lumacaftor/ivacaftor )