Opsismodysplasia: a case report

Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality

This report describes two patients with INPPL1- related skeletal dysplasia diagnosed prenatally. A literature review is conducted to find out if high-lethality is associated with particular pathogenic variants in INPPL1 gene. Prediction of lethality in the prenatal setting has an impact on perinatal management. Some frameshift variants in INPLL1 gene are uniquely observed in lethal cases; however, more patients are needed to confirm the correlation.

INPPL1 gene mutations in opsismodysplasia

The INPPL1 (inositol polyphosphate phosphatase-like 1) gene encodes the inositol phosphatase, SHIP2 (for src homology 2 domain-containing inositol phosphatase 2). SHIP2 functions to dephosphorylate, and negatively regulate, the lipid second messenger phosphatidylinositol (3,4,5)P3. SHIP2 has been well studied in the area of insulin resistance and obesity but has roles in cancer and other disorders. Recently, it was reported that mutations in INPPL1 cause opsismodysplasia, a rare, autosomal recessive severe skeletal dysplasia. This review focuses on the mutations associated with opsismodysplasia and explores the role of INPPL1/ SHIP2 in skeletal development.

A further case of opsismodysplasia with hydrocephalus

We present a case of opsismodysplasia, a very rare skeletal dysplasia, in a term newborn female who had short length, short extremities and markedly short fingers. Radiological studies demonstrated severe platyspondyly, absence of epiphyseal ossification centers, short tubular bones, especially severe in hands and feet, with metaphyseal cupping. She also had hydrocephaly, a rare finding in opsismodysplasia. In our literature review we have found 24 cases, 17 born alive and seven terminations of pregnancy (TOPs).