Table 3 Comparison of pattern of genetic mutations among other similar studies [8,9,10]
Study | No. of patients | Presentation | Peak total serum bilirubin Levels | Response to phenobarbitone | Crigler-Najjar II (UGT1A1 coding region missense mutation) | Gilbert’s syndrome (promoter region mutation) |
|---|---|---|---|---|---|---|
Our case (2019–2023) | One Indian infant | Persistent unconjugated hyperbilirubinemia a from birth | 22.7 mg/dl | Significant > 80% reduction | Homozygous c.164A > G (p. His55Arg) | Homozygous (TA)7TAA/(TA)7TAA |
Abell R et al. (2012) [8] | One (6-day-old American) | Pronounced neonatal hyperbilirubinemia | 20.1 mg/dl | Not significant | 3 mutations Heterozygous *28 (TA 6/7) (c. 40-39insTA) Heterozygous *60 (c-3275 T > G) Heterozygous *93 (c.-3152G > A) | Heterozygous (TA)6TAA/(TA)7TAA |
Chalasani N et al. (1997) [9] | One American boy diagnosed as CN II 3 weeks of age | Kernicterus at 23 years of age | 356 µmol/l | 50% reduction | Heterozygous Single base substitution in one allele of exon 5 at nucleotide 1391 (A–C) and other alleles normal | Homozygous (TA)7TAA/(TA)7TAA |
Kadakol A et al. (2001) [10](four American families) | Family A | |||||
18-month twin 1 | Persistent unconjugated hyperbilirubinemia since birth | 456 µmol | Significant response | 1223delA/normal | (TA)6TAA/(TA)7TAA | |
18-month twin 2 | Persistent unconjugated hyperbilirubinemia since birth | 410 µmol/l | 1223delA/normal | (TA)6TAA/(TA)7TAA | ||
Mother | Asymptomatic | 10 µmol/l | Normal | (TA)6TAA/(TA)7TAA | ||
Father | Asymptomatic | 15 µmol/l | 1223delA/normal | (TA)6TAA/(TA)6TAA | ||
Family B | ||||||
10-year boy | Jaundice | 205 µmol/l | No response | 1490 T > A/normal | (TA)6TAA/(TA)7TAA | |
18-year sister | Mild jaundice | 85 µmol/l | 1490 T > A/normal | (TA)6TAA/(TA)7TAA | ||
Mother | Asymptomatic | 7 µmol/l | Normal | (TA)6TAA/(TA)7TAA | ||
Father | Asymptomatic | 9 µmol/l | 1490 T > A/normal | (TA)6TAA/(TA)6TAA | ||
Family C | ||||||
Infant | Persistent unconjugated hyperbilirubinemia since birth | 359 µmol/l | 80% reduction | 1452G > A/1452G > A | (TA)6TAA/(TA)7TAA | |
Mother | Asymptomatic | 51 µmol/l | 1452G > A/Normal | (TA)6TAA/(TA)7TAA | ||
Father | Asymptomatic | 10 µmol/l | 1452G > A/Normal | (TA)6TAA/(TA)6TAA | ||
Family D | ||||||
Sister 1 | Unconjugated hyperbilirubinemia since birth | 282 µmol/l | Not tried | 524 T > A/524 T > A | (TA)7TAA/(TA)7TAA | |
Sister 2 | Unconjugated hyperbilirubinemia since birth | 203 µmol/l | 524 T > A/524 T > A | (TA)7TAA/(TA)7TAA | ||
Father | Asymptomatic | 60 µmol/l | 524 T > A/Normal | (TA)7TAA/(TA)7TAA | ||