Clinical practice - latest insights in optimizing the care of children with Down syndrome.

An essential part of the care of children with Down syndrome is secondary screening for comorbidity. It is well known that comorbidity frequently occurs in these children. A new update of the Dutch Down syndrome medical guideline was developed to create a sound evidence base for several of these conditions. We present the latest insights and recommendations from this Dutch medical guideline which are based on the most relevant literature currently available and developed with rigorous methodology. The main focus of this revision of the guideline was on obstructive sleep apnea and other airway problems and hematologic disorders, such as transient abnormal myelopoiesis, leukemia, and thyroid disorders. Conclusion: This is a short summary of the latest insights and recommendations from the updated Dutch medical guideline for children with Down syndrome.

The MAP3K7 gene: Further delineation of clinical characteristics and genotype/phenotype correlations.

Mitogen-activated protein 3 kinase 7 (MAP3K7) encodes the ubiquitously expressed transforming growth factor ß-activated kinase 1, which plays a crucial role in many cellular processes. Mutationsin the MAP3K7 gene have been linked to two distinct disorders: frontometaphyseal dysplasia type 2 (FMD2) and cardiospondylocarpofacial syndrome (CSCF). The fact that different mutations can induce two distinct phenotypes suggests a phenotype/genotype correlation, but no side-by-side comparison has been done thus far to confirm this. Here, we significantly expand the cohort and the description of clinical phenotypes for patients with CSCF and FMD2 who carry mutations in MAP3K7. Our findings support that in contrast to FMD2-causing mutations, CSCF-causing mutations in MAP3K7 have a loss-of-function effect. Additionally, patients with pathogenic mutations in MAP3K7 are at risk for (severe) cardiac disease, have symptoms associated with connective tissue disease, and we show overlap in clinical phenotypes of CSCF with Noonan syndrome (NS). Together, we confirm a molecular fingerprint of FMD2- versus CSCF-causing MAP3K7 mutations and conclude that mutations in MAP3K7 should be considered in the differential diagnosis of patients with syndromic congenital cardiac defects and/or cardiomyopathy, syndromic connective tissue disorders, and in the differential diagnosis of NS.