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Radiology
Chromosome 5p Deletion Syndrome (Cri du Chat Syndrome)
Built from Obstetric Imaging
What’s inside
8 sections · 79 slides
Overview
- What you will learn here
A missing piece of chromosome 5
What the condition is, what it is called, and how often it happens
- The basic problem: one chromosome is short
- Where the old name comes from
- How the syndrome is defined
- 1:15,000
- Reading those frequency numbers
- Why this now matters before birth
What is missing, and how it goes missing
Deletion size, how it arises, and the tests that find it
- How big is the missing piece
- The four ways the piece is lost
- The numbers behind each mechanism
- Which parent's chromosome is affected
- When the deletion runs in a family
- Which part of the arm does what
- Why the outlook is hard to predict early
- The three laboratory tests
- Why microarray is the first choice
- Screening in a low-risk pregnancy
- 75%
- Why a positive screen still needs a test
- From a positive screen to a firm answer
- The complication of mosaic deletions
The baby and the child
What the syndrome looks like after birth, and how it unfolds
- The newborn picture
- Why the cry sounds like that
- The face
- Most of the face cannot be seen before birth
- Structural problems that occur less often
- What maternal blood screening may hint at
- Problems in the first months
- Behaviour and the longer view
- The classic signs and how common they are
- The classic facial features by frequency
- Which classic signs a scan can pick up
What prenatal imaging shows
Ultrasound findings, their reported frequency, and what MRI adds
- Why these scan findings are easy to miss
- How to use the frequency list that follows
- Prenatal Ultrasound Findings Associated With 5p Deletion Syndrome
- Prenatal Ultrasound Findings Associated With 5p Deletion Syndrome (continued)
- Clues in growth, head size and the profile
- Small head with an abnormal facial profile
- The small jaw seen in profile
- Widely spaced fetal orbits
- Soft markers: small clues, not diagnoses
- Missing nasal bone on the profile view
- Cysts in the choroid plexus
- Mild widening of the lateral ventricle
- Thick nuchal fold with a cystic hygroma
- The heart: the commonest organ affected
- A small hole between the ventricles
- The brain: what to look for behind the head
- Enlarged posterior fossa with a missing vermis
- Brain tissue pushing through a skull defect
- Rarer findings still worth naming
- Bilateral cleft lip on 3D ultrasound
- Wedge-shaped vertebrae in the fetal spine
- Inward curve of the little finger
- The scan clues gathered in one place
- When MRI adds something
- What 3D ultrasound adds
- Two directions the diagnosis can travel
Conditions that can look the same
Why the imaging picture is never enough on its own
- The differential diagnosis is broad
- How to use that list
Counselling, delivery and care
What can be offered before birth, at birth, and afterwards
- Before birth there is no treatment
- Planning the birth itself
- Why smaller deletions need extra care
- Supportive care after birth
- What early intervention achieves
- 5-9%
- What those survival figures mean
- Support beyond the hospital
- What happens after a new diagnosis
- What the referring physician needs to know
- The family conversation that must follow
Key points
The short list worth carrying out of this topic
- Key points: the condition
- Key points: testing and counselling
- Key points: after the baby arrives
- References
- References (continued)
- References (continued)
- References (continued)
- Obstetric Imaging: Fetal Diagnosis and Care, 2nd Edition