A hypomorphic inherited pathogenic variant in DDX3X causes male intellectual disability with additional neurodevelopmental and neurodegenerative features

Table 1 Summary of clinical findings in the two subjects. Human phenotype ontology (HPO) terms and codes are shown

Phenotype	HPO code	Case 1	Case 2
Intellectual disability or related neurodevelopmental disability	HP:0001256	+	+
Macrocephaly	HP:0000256	+	+
Dysarthria	HP:0001260	+	+
Tight heel cords		+	+
Progressive spastic paraparesis	HP:0007199	+	+
Tremor	HP:0002322	–	+
Hand weakness	HP:0030237	+	–
Proximal leg weakness	HP:0007340	+	+
Brain MRI with abnormal periventricular T2 intensity	HP:0002518	+	+
Ventriculomegaly	HP:0002119	+	+
Atrophy of corpus callosum, esp. the genu and anterior body of corpus callosum	HP:0006989	+	+
Increased cerebrospinal fluid alanine level	n/a	+	+

ISSN: 1479-7364