ABSTRACT
Richner-Hanhart syndrome (tyrosinemia type 2) is an inborn error of tyrosine metabolism which is clinically characterized mainly by oculocutaneous symptoms including corneal opacities and keratosis palmoplantaris. Skin symptoms usually develop after the first year of life. We report a neonate in whom already on the third day of life diagnosis of Richner-Hanhart syndrome could be suspected because of elevated tyrosine levels in newborn screening by tandem mass spectrometry. Analysis of the tyrosine aminotransferase gene revealed a homozygous missense mutation p.R433W (c.1297C>T). An 8-year-old brother with persistent plantar hyperkeratotic plaques of the soles of yet unknown origin was subsequently identified to be also affected with Richner-Hanhart syndrome. This demonstrates that early diagnosis of Richner-Hanhart syndrome is possible in neonates by extended newborn screening. Early introduction of dietary treatment is a prerequisite to reduce the risk of clinical symptoms.
Subject(s)
Neonatal Screening , Tyrosine/blood , Tyrosinemias/diagnosis , Child , Eye Diseases/etiology , Female , Humans , Infant, Newborn , Keratoderma, Palmoplantar/etiology , Keratoderma, Palmoplantar/pathology , Male , Mutation, Missense , Polymerase Chain Reaction , Skin/pathology , Tandem Mass Spectrometry , Tyrosine Transaminase/genetics , Tyrosinemias/complications , Tyrosinemias/geneticsABSTRACT
The 22q11.2 deletion syndrome is one of the most frequent genetic syndromes, mainly characterized by cleft palate, facial dysmorphism, conotruncal heart malformations and immune deficiencies. Microduplication of the 22q11.2 region is a quite recently characterized genetic entity comprising a variable phenotype including some overlapping features with the 22q11.2 deletion syndrome. So far only few reports of patients with this microduplication and heart defects have been published. To our knowledge this is the first description of a patient with genetically confirmed duplication of the 22q11.2 region and d-transposition of the great arteries (d-TGA) as well as Ebstein's anomaly.
