49,XYYYY syndrome
MONDO:002047049,XYYYY is a rare Y chromosome number anomaly with a variable phenotype mainly characterized by moderate to severe intellectual disability, speech delay, hypotonia, and mild dysmorphic features, including facial asymmetry, hypertelorism, bilateral low set 'lop' ears, and micrognatia. Skeletal abnormalities (such as skull deformities, radioulnar synostosis, elbow flexion, clinodactyly, brachydactyly) and behavourial problems have also been associated with this condition. Genitalia are normal at birth, although hypogonadism and azoospermia has been reported in adults.
6 clinical trials for this condition and its sub-types, 0 tagged with 49,XYYYY syndrome itself.
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A simple blood draw could one day detect down syndrome in pregnancy
Diagnosis Recruiting nowResearchers are collecting blood samples from pregnant women at higher risk of having a baby with a chromosomal condition. The goal is to develop a noninvasive prenatal test that looks at cell-free DNA in the mother's blood to detect Down syndrome. Participants give blood between…
Sponsor: Sequenom, Inc. • Aim: Diagnosis
Last updated Sep 11, 2026 00:00 UTC
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New prenatal blood test aims to detect genetic disorders without invasive procedures
Diagnosis Recruiting nowThis study is testing a new blood test that looks for fetal cells in the mother's blood to detect genetic conditions like Down syndrome. The test will be compared to standard diagnostic methods such as amniocentesis or newborn testing. The study involves 1,000 pregnant individual…
Sponsor: BillionToOne Inc. • Aim: Diagnosis
Last updated Jun 27, 2026 13:06 UTC
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Social coaching may ease anxiety and autism traits in rare chromosome conditions
Symptom relief Recruiting nowThis trial tests whether a 10-session group program called Social Management Training can improve mental health, executive function, and social skills in adults aged 16 to 69 who have sex chromosome aneuploidies (extra or missing sex chromosomes). Participants complete questionna…
Phase 1 • Sponsor: University of Oslo • Aim: Symptom relief
Last updated Jul 24, 2026 00:00 UTC