Clinical Guidance
INPPL1-related opsismodysplasia is characterized by prenatal-onset short stature, short limbs, small hands and feet, narrow thorax, dysmorphic facial features (including relative macrocephaly, prominent forehead, midface retrusion, depressed nasal bridge, short nose, anteverted nares, and relatively long philtrum), delayed epiphyseal mineralization, metaphyseal cupping, and platyspondyly. To date, 35 individuals have been identified with biallelic pathogenic variants in INPPL1 [, , , , , , , ]. The following description of the phenotypic features associated with this condition is based on these reports. Table 2. INPPL1-Related Opsismodysplasia: Frequency of Select Features
Feature | % of Persons w/Feature | Comment |
|---|
Short stature | 10/10 | — |
Short long bones | 15/19 | Long bones are often bowed. |
Short hands/feet | 18/20 | — |
Delayed epiphyseal mineralization | 18/20 | — |
Metaphyseal cupping | 17/20 | — |
Platyspondyly | 13/18 | — |
Small/narrow thorax | 7/19 | — |
Renal phosphate wasting/ hypophosphatemia | 7/10 | — |
Respiratory issues | 15/20 | Prenatal. Reported prenatal ultrasound findings reflect the underlying skeletal differences, including short limbs, short long bones, short hands and feet, narrow thorax, bell-shaped thorax, platyspondyly, and decreased bone echogenicity. |
Source: GeneReviews — "INPPL1-Related Opsismodysplasia"
