Rapid Progression of Heterotopic Ossification in Severe Variant of Fibrodysplasia Ossificans Progressiva with p.Arg258Gly in ACVR1: A Case Report and Review of Clinical Phenotypes

Table 1

Clinical characteristics of severe FOP patients with the heterozygous p.Arg258Gly variant of ACVR1.

		[7]		Present case
		Patient 1	Patient 2
Variant/mode of inheritance		Heterozygous c.772G > A; p.Arg258Gly/de novo
Chromosome		46, XX	46, XY	46, XX
Age at onset of heterotopic ossification		16 months	11 months	9 months
Heterotopic ossification-induced multiple joint contracture		+
Fusion of cervical vertebra		+
Four-limb digit reduction anomalies with no nails and soft tissue syndactyly		+
Dysmorphic facial features	Microretrognathia	+
	Low-set dysmorphic ears	+
	Hypertelorism	−	+	−
	Depressed nasal bridge	+	−	+
	Sparse hair	+
	Small malformed teeth	+
Brain anomalies	Hypoplasia of brainstem	+	n.a.	+
	Hydrocephalus	+	n.a.	+
	Agenesis/hypoplasia of corpus callosum		+	+
Craniosynostosis		n.a.	+	-
Patent ductus arteriosus		−	+	+
Genital anomalies		−	+	−
Sensorineural hearing loss		+	n.a.	+
Gross motor delay		+
Other malformations			Left renal duplication