Undiagnosed Phenylketonuria Can Exist Everywhere: Results From an International Survey

peer reviewedMany countries do not have a newborn screening (NBS) program, and immigrants from such countries are at risk for late diagnosis of phenylketonuria (PKU). In this international survey, 52 of 259 patients (20%) with late diagnosed PKU were immigrants, and 145 of the 259 (55%) were born before NBS or in a location without NBS. © 2021 The Author

Genotype-phenotype correlations of cystic fibrosis in siblings compound heterozygotes for rare variant combinations: Review of literature and case report

Here, we describe a cystic fibrosis (CF) family with affected siblings, two of whom have a combination of I1234V and 1677delTA variants with classic CF features, the third child with a combination of I1234V and L997F variants with atypical CF, and the apparently healthy mother with a combination of 1677delTA and L997F alleles. Interestingly, the sibling with I1234V and L997F variants had normal sweat test results and had a much milder phenotype than the other two siblings with I1234V and 1677delTA variants, suggesting that this combination is causative for atypical CF. The fact that their mother with the combination of 1677delTA and L997F appears to be healthy suggests that the L997F variant causes different phenotypes in different allele combinations. The current cases show that there is a genotype-phenotype correlation in this disease and underline the importance of genotyping individuals with suspected CF to allow prediction of disease severity and effective treatment

Undiagnosed Phenylketonuria Can Exist Everywhere: Results From an International Survey

Many countries do not have a newborn screening (NBS) program, and immigrants from such countries are at risk for late diagnosis of phenylketonuria (PKU). In this international survey, 52 of 259 patients (20%) with late diagnosed PKU were immigrants, and 145 of the 259 (55%) were born before NBS or in a location without NBS

Genomic analyses in Cornelia de Lange Syndrome and related diagnoses: Novel candidate genes, genotype-phenotype correlations and common mechanisms.

Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (>60%) of cases, and the only gene identified to date that results in the severe or classic form of CdLS when mutated. Pathogenic variants in cohesin genes other than NIPBL tend to result in a less severe phenotype. Causative variants in additional genes, such as ANKRD11, EP300, AFF4, TAF1, and BRD4, can cause a CdLS-like phenotype. The common role that these genes, and others, play as critical regulators of developmental transcriptional control has led to the conditions they cause being referred to as disorders of transcriptional regulation (or "DTRs"). Here, we report the results of a comprehensive molecular analysis in a cohort of 716 probands with typical and atypical CdLS in order to delineate the genetic contribution of causative variants in cohesin complex genes as well as novel candidate genes, genotype-phenotype correlations, and the utility of genome sequencing in understanding the mutational landscape in this population