[Genetic analysis of three patients with Kleefstra syndrome].

OBJECTIVE: To analyze the clinical and genetic features of three patient diagnosed with Kleefstra syndrome. METHODS: Whole exome sequencing (WES) was carried out for the probands and their parents. Suspected variants were validated by Sanger sequencing. Copy number variations (CNV) were detected by CNV-seq and validated by real-time PCR. RESULTS: Proband 1 was found to carry a de novo heterogeneous variant (c.823+1G>T) of the EHMT1 gene, which may affect its expression. Based on the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PS2+PM2). Proband 2 was found to carry a de novo missense variant c.439C>G (p.L147V) of the EHMT1 gene, which was predicted to be likely pathogenic (PS2+PM1+PM2+PP3). Proband 3 was found to carry a heterozygous 520 kb deletion at 9q34.3 by CNV-seq. The deletion has encompassed the whole of the EHMT1 gene. Real-time PCR has detected no CNV of this region in her parents. CONCLUSION: Variants of the EHMT1 gene probably underlay the disease in these patients. Genetic testing has provided a basis for their clinical diagnosis.

II. SAR studies of pyridyl-piperazinyl-piperidine derivatives as CXCR3 chemokine antagonists.

The structure-human CXCR3 binding affinity relationship of a series of pyridyl-piperazinyl-piperidine derivatives was explored. The optimization campaign highlighted the pronounced effect of 2'-piperazine substitution on CXCR3 receptor affinity. Analog 18j, harboring a 2'(S)-ethylpiperazine moiety, exhibited a human CXCR3 IC(50) of 0.2 nM.

III. Identification of novel CXCR3 chemokine receptor antagonists with a pyrazinyl-piperazinyl-piperidine scaffold.

The SAR of a novel pyrazinyl-piperazinyl-piperidine scaffold with CXCR3 receptor antagonist activity was explored. Optimization of the DMPK profile and reduction of hERG inhibition is described. Compound 16e with single-digit CXCR3 affinity, good rat PK and hERG profiles has been identified as a lead for further study.

Discovery of 2-aminoimidazopyridine adenosine A(2A) receptor antagonists.

A novel series of adenosine A(2A) receptor antagonists was identified by high-throughput screening of an encoded combinatorial compound collection. The initial hits were optimized for A(2A) binding affinity, A(1) selectivity, and in vitro microsomal stability generating orally available 2-aminoimidazo[4,5-b]pyridine-based A(2A) antagonist leads.

Novel CXCR3 antagonists with a piperazinyl-piperidine core.

High-throughput screening of an encoded combinatorial aryl piperazine library led to the identification of a novel series of potent piperazinyl-piperidine based CXCR3 antagonists. Analogs of the initial hit were synthesized via solid and solution phase methods to probe the influence of structure on the CXCR3 binding of these molecules. Various functional groups were found to contribute to the overall potency and essential molecular features were identified.

Small molecule biaryl FSH receptor agonists. Part 1: Lead discovery via encoded combinatorial synthesis.

High-throughput screening of two million compounds in 37 distinct encoded combinatorial libraries using FSH receptor transfected cells provided small molecule agonists such as 1 (EC(50)=3 microM) and 2 (EC(50)=3.9 microM), based on which a focused combinatorial library with a total of 31372 compounds was designed, synthesized, and screened to reveal 72 novel biaryl FSH receptor agonists such as 8a-c as well as a unique combinatorial SAR.

Small molecule biaryl FSH receptor agonists. Part 2: Lead optimization via parallel synthesis.

Potent small molecule biaryl diketopiperazine FSH receptor agonists such as 10c (EC(50)=13 nM) and 11f (EC(50)=1.2 nM) were discovered through the design, synthesis and evaluation of three biaryl diketopiperazine optimization libraries with over 300 compounds. These libraries were prepared via solid-phase parallel synthesis using a cyclization-release method.

2-(Aminomethyl)-benzamide-based glycine transporter type-2 inhibitors.

Structure-activity studies on benzamide 1 obtained from library screening led to the discovery of a novel series of potent and selective glycine transporter type-2 inhibitors.