📄 SCRS

Casamassima-Morton-Nance
syndrome

Casamassima-Morton-Nance syndrome ultrasound case study

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Reporting Panel

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Fetal Pathology

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USG

Casamassima-Morton-Nance syndrome ultrasound case study

CASE–1

Clinical History

A fetus was referred for a detailed fetal anomaly scan because of severe skeletal abnormalities detected on routine antenatal ultrasound. The examination was performed to evaluate the fetal thoracic cage, vertebral column, ribs, limbs, abdominal wall, and associated anomalies.

Ultrasound Findings

Ultrasound examination demonstrates multiple thoracic and lumbar vertebral segmentation anomalies with severe thoracolumbar scoliosis. The thoracic cage is markedly small with severe thoracic hypoplasia due to multiple absent and malformed ribs. A large anterior abdominal wall defect consistent with gastroschisis is present, with herniation of bowel loops into the amniotic cavity. Unilateral complete absence of the lower limb (amelia) is demonstrated. The combination of severe vertebral and rib anomalies, markedly reduced thoracic volume, anterior abdominal wall defect, and lower limb deficiency is highly suggestive of Casamassima-Morton-Nance syndrome (Spondylocostal dysostosis with anal, urogenital, and limb anomalies).

Fetal ultrasound. Multiple thoracic vertebral segmentation anomalies are present with marked thoracic scoliosis/kyphoscoliosis, a short hypoplastic thorax with absent/fused ribs, and a shortened trunk consistent with short-trunk dwarfism . Complete absence (only soft tissue stump is seen) of both lower limb is also noted Amelia . The constellation of findings is suggestive of Casamassima-Morton-Nance syndrome; however, complete lower-limb absence is not a classic feature of this syndrome and may indicate an expanded phenotypic spectrum or an alternative diagnosis.

Coronal plane. A marked ventral abdominal wall defect (omphalocele) is demonstrated, with herniation of bowel into a membrane-covered sac anterior to the fetal abdomen. The associated omphalocele supports the diagnosis of a complex congenital malformation syndrome.

Report Line

Multiple thoracic vertebral segmentation anomalies are identified with marked thoracic scoliosis/kyphoscoliosis. The thoracic cage is markedly shortened with absent/fused ribs, resulting in severe thoracic hypoplasia and short-trunk dwarfism. Complete bilateral lower-limb amelia (only soft tissue stumps are identified) is demonstrated. A large anterior abdominal wall defect (omphalocele) containing herniated bowel within a membrane-covered sac is also present. The constellation of findings is most suggestive of Casamassima-Morton-Nance syndrome. However, complete bilateral lower-limb amelia is not a classic feature of this syndrome and may represent an expanded phenotypic spectrum or an alternative diagnosis.

Impression

Features are most consistent with Casamassima-Morton-Nance syndrome.
[D/D Jarcho–Levin syndrome, Limb–Body Wall Complex or OEIS complex.]

Recommendation

A detailed fetal anomaly survey is recommended to evaluate for additional skeletal, cardiac, craniofacial, renal, and central nervous system abnormalities. Fetal echocardiography and fetal MRI may be considered for comprehensive assessment of associated anomalies. Genetic counseling is advised, with consideration of chromosomal microarray analysis and molecular genetic testing. Multidisciplinary prenatal counseling should be offered to discuss the guarded prognosis associated with severe thoracic insufficiency and multiple congenital anomalies.

Key Learning Points

• Casamassima-Morton-Nance syndrome is a rare skeletal dysplasia characterized by multiple vertebral segmentation defects, rib anomalies, and short-trunk dwarfism.
• Marked thoracic scoliosis/kyphoscoliosis with a short hypoplastic thorax may result in severe thoracic insufficiency.
• Associated anomalies may include omphalocele and other visceral, cardiac, or genitourinary malformations.
• Complete bilateral lower-limb amelia is not a classic feature and may represent an expanded phenotypic spectrum or an alternative diagnosis.
• Assessment should include the vertebral column, ribs, thoracic circumference, abdominal wall, limbs, heart, kidneys, and central nervous system.
• Fetal MRI and fetal echocardiography can aid in comprehensive evaluation of associated anomalies.
• Genetic counseling and molecular genetic testing are recommended to establish the diagnosis and assist with prenatal counseling.