Clinical problem

Clinical problem-1- : A 2 month old boy born of non-consanguineous marriage presented with generalized tonic convulsions. He had no history of fever, refusal of feeds, lethargy. He had similar episode of Day 5 of life and was diagnosed to have aspiration pneumonia and treated with IV Antibiotics and IV Fluids. He had a normal birth and had achieved milestones as per age. On examination, he had an open anterior fontanelle (3 x 3 cm) as well as open posterior fontanelle. He had strawberry hemangioma over scalp and right ankle. He had dysmorphic features in form of mongloid slant, bilateral simian crease, microcephaly with sutural overriding, retrognathia, overriding of 2nd toe over 3rd toe and 4th finger over 5th finger, cortical thumb, sacral dimple and left sided inguinal hernia (with generalized hypotonia. Cardiovascular system examination revealed pansystolic murmur at apex. Other systemic examination was normal. His investigations showed anemia (Hemoglobin = 6.6 gm/dl) with normal WBC and platelet count. He had hypocalcemia (serum calcium = 8.8 mg%) with ionic calcium of 0.98 mmoL/Lit and normal phosphorus and alkaline phosphatase. His serum creatinine was 3.6 mg% with blood urea Nitrogen of 45 mg% and had hyperkalemia (5.9 meq/L) with hyponatremia (112 meq/L) and metabolic acidosis (pH = 6.846, bicarbonate = 3.5 meq/L). Ultrasound of abdomen showed left absent kidney with right sided multicystic dysplastic kidneys. Urine showed 2+ albuminuria. His liver function tests, CSF analysis and X-Ray spine showed vertebral defects. X-Ray Chest showed multiple rib anomalies and echocardiogram showed perimembranous ventricular septal defect with atrial septal defect and patent ductus arteriosus. A karyotype done was normal. He was thus diagnosed to have chronic renal failure due to renal anomalies with congenital heart disease, multiple rib and vertebral anomalies, inguinal hernia with dysmorphic features and hypocalcemic convulsions. He was treated with Sodamint, Calcium supplements, Digoxin, Furosemide and Iron supplements.

Question:

What is the genetic disorder ?