title: The Association of Pseudohypoparathyroidism Type Ia with Chiari Malformation Type I: A Coincidence or a Common Link?
abstract: A 19-month-old boy was referred for progressive weight gain. His past medical history included congenital hypothyroidism and developmental delay. Physical examination revealed characteristics of Albright Hereditary Osteodystrophy, macrocephaly, and calcinosis cutis. He had hypocalcemia, hyperphosphatemia, and elevated Parathyroid Hormone levels. Genetic testing revealed a known mutation of GNAS gene, confirming the diagnosis of Pseudohypoparathyroidism Type Ia (PHP-Ia) (c.34C>T (p.G1n12X)). He had a normal brain MRI at three months, but developmental delay prompted a repeat MRI that revealed Chiari Malformation Type I (CM-I) with hydrocephalus requiring neurosurgical intervention. This was followed by improvement in attaining developmental milestones. Recently, he was diagnosed with growth hormone deficiency. This case suggests the potential association of CM-I with PHP-Ia. Larger studies are needed to assess whether CM-I with hydrocephalus are common associations with PHP-Ia and to define potential genetic links between these conditions. We propose a low threshold in performing brain MRI on PHP-1a patients, especially those with persistent developmental delay to rule out CM-I. Early intervention may improve neurodevelopmental outcomes and prevent neurosurgical emergencies.
authors.affiliation: Department of Pediatrics, McMaster University, Hamilton, ON, Canada.
authors.forename: Paria
authors.identifier: 0000-0003-4490-8080
authors.initials: P
authors.lastname: Kashani
authors.affiliation: Department of Pediatrics, McMaster University, Hamilton, ON, Canada.
authors.forename: Madan
authors.identifier: 0000-0002-3015-5500
authors.initials: M
authors.lastname: Roy
authors.affiliation: Department of Pediatrics, McMaster University, Hamilton, ON, Canada.
authors.forename: Linda
authors.identifier: 0000-0002-6835-488X
authors.initials: L
authors.lastname: Gillis
authors.affiliation: Division of Neurosurgery, McMaster Children's Hospital, Hamilton, ON, Canada.
authors.forename: Olufemi
authors.identifier: 0000-0001-5795-417X
authors.initials: O
authors.lastname: Ajani
authors.affiliation: Division of Pediatric Endocrinology, McMaster Children's Hospital, Hamilton, ON, Canada.
authors.forename: M Constantine
authors.identifier: 0000-0002-6403-4715
authors.initials: MC
authors.lastname: Samaan