Infantile hemiparesis and porencephaly due to a COL4A1 mutation: Gould syndrome

Gould syndrome is an autosomal dominant syndrome due to a COL4A1 or COL4A2 mutation that is commonly characterised by familial porencephaly, seizures, intracranial haemorrhages, cataracts, nephropathies and more. There have been up to 137 identified patients based on a review of the literature. In this case, we describe a male infant that presents with hemiparesis, developmental delay and gait abnormalities at his well-child check. Referral to neurology and a subsequent MRI demonstrated porencephaly and ocular lens abnormalities. Genetic sequencing uncovered a mutation to the COL4A1 gene, suggesting Gould syndrome. There are no family members with similar phenotypes. Mutations to the COL4A1 and COL4A2 genes result in disruption of collagen found in most basement membranes, resulting in a variety of phenotypes that can make diagnosis difficult. Genetic identification of these patients is critical as these patients require a multidisciplinary approach to care and specific counselling on risk reduction techniques.

Prevalence of COL4A1 and COL4A2 mutations in severe fetal multifocal hemorrhagic and/or ischemic cerebral lesions

OBJECTIVE

To establish the prevalence of COL4A1 and COL4A2 gene mutations in fetuses presenting with a phenotype suggestive of cerebral injury.

METHODS

This was a single-center retrospective analysis of all cases of fetal cerebral anomalies suggestive of COL4A1 or COL4A2 gene mutation over the period 2009-2018. Inclusion criteria were: (1) severe and/or multifocal hemorrhagic cerebral lesions; (2) multifocal ischemic-hemorrhagic cerebral lesions. These anomalies could be of different ages and associated with schizencephaly or porencephaly. Between fetuses with and those without a mutation, we compared gestational age at the time of diagnosis, parity and fetal gender.

RESULTS

Among the 956 cases of cerebral anomaly diagnosed in our center during the 10-year study period, 18 fetuses were identified for inclusion. A pathogenic COL4A1 gene mutation was found in five of these cases, among which four were de-novo mutations. A variant of unknown significance was found in four fetuses: in the COL4A1 gene in one case and in the COL4A2 gene in three cases. No COL4A1 or COL4A2 mutation was found in the remaining nine fetuses. The median (interquartile range) gestational age at diagnosis was significantly lower in cases with a mutation (24 (22-26) weeks) than in cases without a mutation (32 (29.5-34.5) weeks) (P = 0.03).

CONCLUSIONS

A phenotype suggestive of cerebral injury was found in 18 of the 956 (1.9%) cases in our population, in 28% of which there was an associated COL4A1 or COL4A2 mutation. COL4A1 and COL4A2 gene mutations should be sought systematically in cases of severe and/or multifocal hemorrhagic or ischemic-hemorrhagic cerebral lesions, with or without schizencephaly or porencephaly. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Life-threatening muscle complications of COL4A1-related disorder

COL4A1-related disorder is recognized as a systemic disease because the alpha 1 chain of type IV collagen, encoded by COL4A1, is essential for basement membrane stability. However, muscular manifestations related to this disorder are rarely reported. We report the case of a 2-year-old boy with porencephaly, who harbored a de novo COL4A1 mutation of c.1853G > A, p. (Gly618Glu) and exhibited recurrent rhabdomyolysis with viral or bacterial infections. Moreover, he developed obstructive hypertrophic cardiomyopathy which required surgical intervention. Skeletal muscle biopsy revealed findings compatible with fiber-type disproportion. Ultrastructural study demonstrated the similar findings previously reported in mice with Col4a1 mutation including collagen disarray and reduction of electron density in the basement membrane of capillary endothelial cells and muscle fibers. Dilated endoplasmic reticulum in the capillary endothelial cells is also noted. This report adds another disease spectrum of COL4A1 mutation which include porencephaly, hypertrophic cardiomyopathy, rhabdomyolysis and fiber-type disproportion.

A mutation in COL4A2 causes autosomal dominant porencephaly with cataracts

Mutations in COL4A1 are well described and result in brain abnormalities manifesting with severe neurological deficits including cerebral palsy, intellectual disability, and focal epilepsy. Families with mutations in COL4A2 are now emerging with a similar phenotype. We describe a family with an autosomal dominant disorder comprising porencephaly, focal epilepsy, and lens opacities, which was negative for mutations in COL4A1. Using whole exome sequencing of three affected individuals from three generations, we identified a rare variant in COL4A2. This COL4A2 (c.2399G>A, p.G800E, CCDS41907.1) variant was predicted to be damaging by multiple bioinformatics tools and affects an invariable glycine residue that is essential for the formation of collagen IV heterotrimers. The cataracts identified in this family expand the phenotypic spectrum associated with mutations in COL4A2 and highlight the increasing overlap with phenotypes associated with COL4A1 mutations.