Tyrosinemia Clinical Presentation

Updated: Aug 08, 2017
  • Author: Karl S Roth, MD; Chief Editor: Luis O Rohena, MD, MS, FAAP, FACMG  more...
  • Print
Presentation

History

Failure to thrive may precede the appearance of more dramatic findings in tyrosinemia. Patients with such findings often have a history of diminished nutritional intake and anorexia.

The patient then develops vomiting and diarrhea, which rapidly progress to bloody stool, lethargy, and jaundice. At this stage, a distinctive cabbagelike odor may be appreciated.

At approximately age 1 year, infants with the chronic form may have failure to thrive and delayed walking, which may indicate rickets.

Because the disease is autosomal recessive, the family pedigree typically does not reveal previously affected individuals. However, a French-Canadian ancestry should raise suspicion because of the extraordinarily high incidence of heterozygotes in the adult population of this lineage.

Next:

Physical

Clinical suspicion should be extremely high in infants with failure to thrive and hepatomegaly in the first 3 months of life.

The acute onset may be dramatic, with hepatomegaly, jaundice, epistaxis, melena, purpuric lesions, marked edema, and the distinctive cabbagelike odor.

Because of the inhibitory effects of succinylacetone on the heme biosynthetic pathway, infants with the chronic form may develop polyneuropathy and painful abdominal crises, as seen in acute intermittent porphyria.

Survivors may have hepatic nodules and cirrhosis; the nodules may indicate hepatocellular carcinoma. Distant metastases can occur.

Previous
Next:

Causes

The sole explanation for tyrosinemia I is genetic mutation in homozygous form. Heterozygote individuals are entirely unaffected.

The gene is mapped to band 15q23-q25, and approximately 95 distinct mutations have been reported, with no clear relationship between genotype and phenotype.

Previous