title: Diagnostic challenges in a severely delayed infant with hypersomnolence, failure to thrive and arteriopathy: a unique case of gamma-hydroxybutyric aciduria and Williams syndrome.
abstract: Metabolic work-up, pursued in a 5-month-old female infant with hypersomnolence, failure to thrive, and global developmental delay, led to the identification of gamma-hydroxybutyric aciduria (GHB). Succinic semialdehyde dehydrogenase deficiency (SSADH deficiency) was confirmed enzymatically and molecularly. Characteristic dysmorphic facies, cardiovascular anomalies, and hypercalcemia led to clinical suspicion of Williams-Beuren syndrome (WS), confirmed by cytogenetic studies. This rare occurrence of two unrelated genetic conditions highlights the importance of instituting comprehensive metabolic studies despite the presence of syndromic findings, even in the absence of other metabolic abnormalities that may be indicative of metabolic disease such as hyperammonemia, hypoglycemia, ketonuria, and metabolic acidosis.
authors.affiliation: Children's and Adolescents' Hospital, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Ina
authors.initials: I
authors.lastname: Knerr
authors.forename: K Michael
authors.initials: KM
authors.lastname: Gibson
authors.forename: Jaya
authors.initials: J
authors.lastname: Ganesh
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bennett
authors.forename: Gajja S
authors.initials: GS
authors.lastname: Salomons
authors.forename: Cornelis
authors.initials: C
authors.lastname: Jakobs
authors.forename: Scott M
authors.initials: SM
authors.lastname: Myers
mesh_terms: D021921:Aortic Stenosis, Supravalvular / Q000175:diagnosis; D002658:Developmental Disabilities / Q000175:diagnosis; D003937:Diagnosis, Differential; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis*; D005183:Failure to Thrive / Q000175:diagnosis*; D005260:Female; D006801:Humans; D006885:Hydroxybutyrates / Q000378:metabolism*; D007223:Infant; D008661:Metabolism, Inborn Errors / Q000175:diagnosis / Q000378:metabolism; D050644:Succinate-Semialdehyde Dehydrogenase / Q000172:deficiency*; D018980:Williams Syndrome / Q000175:diagnosis*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D006885:Hydroxybutyrates; C111420:4-hydroxybutyric acid; D005680:gamma-Aminobutyric Acid; D050644:Succinate-Semialdehyde Dehydrogenase