Filippi syndrome: Three new families suggest that urinary system abnormalities may belong to clinical spectrum of the disease

Filippi syndrome is a rare genetic disorder characterized by growth and neurodevelopmental delays, dysmorphism, and selective limb abnormalities. Although the syndrome was described approximately four decades ago, only a few families with molecularly confirmed diagnoses have been reported. In this article, we present three new patients of Filippi syndrome with unusual clinical and genetic aspects. These patients exhibited novel clinical features that have not previously been associated with Filippi syndrome, including renal hypoplasia/aplasia, renal cysts, renal cortical thinning, hypomelanotic, and hypermelanotic macules. All three patients had homozygous frameshift variants of the CKAP2L gene, specifically NM_152515.3: c.554_555del, c.981_982del, and c.1463_1467del, with the second being a novel variant. Given the limited number of reported Filippi syndrome patients to date and the ongoing discovery of new clinical aspects of the disease, exploring its potential connection with kidney and skin pigmentation abnormalities could be valuable for future research.

Skin Pigmentation Abnormalities and Their Possible Relationship with Skin Aging

Skin disorders showing abnormal pigmentation are often difficult to manage because of their uncertain etiology or pathogenesis. Abnormal pigmentation is a common symptom accompanying aging skin. The association between skin aging and skin pigmentation abnormalities can be attributed to certain inherited disorders characterized by premature aging and abnormal pigmentation in the skin and some therapeutic modalities effective for both. Several molecular mechanisms, including oxidative stress, mitochondrial DNA mutations, DNA damage, telomere shortening, hormonal changes, and autophagy impairment, have been identified as involved in skin aging. Although each of these skin aging-related mechanisms are interconnected, this review examined the role of each mechanism in skin hyperpigmentation or hypopigmentation to propose the possible association between skin aging and pigmentation abnormalities.