Familial renal hypophosphatemia, minor facial anomalies, intracerebral calcifications, and non-rachitic bone changes: apparently new syndrome?

Diagnosis and initial management of children presenting with premature loss of primary teeth associated with a systemic condition: A scoping review and development of clinical aid

BACKGROUND

Premature loss of primary teeth (PLPT) can be a rare presentation of systemic medical conditions. Premature loss of primary teeth may present a diagnostic dilemma to paediatric dentists.

AIMS

To identify systemic conditions associated with PLPT and develop a clinical aid.

DESIGN

OVID Medline, Embase and Web of Science were searched up to March 2023. Citation searching of review publications occurred. Exclusion occurred for conference abstracts, absence of PLPT and absence of English-language full text.

RESULTS

Seven hundred and ninety-one publications were identified via databases and 476 by citation searching of review articles. Removal of 390 duplicates occurred. Following the exclusion of 466 records on abstract review, 411 publications were sought for retrieval, of which 142 met inclusion criteria. Thirty-one systemic conditions were identified. For 19 conditions, only one publication was identified. The majority of publications, 91% (n = 129), were case reports or series. Most publications, 44% (n = 62), were related to hypophosphatasia, and 25% (n = 35) were related to Papillon-Lefèvre. Diagnostic features were synthesised, and a clinical aid was produced by an iterative consensus approach.

CONCLUSIONS

A diverse range of systemic diseases are associated with PLPT. Evidence quality, however, is low, with most diseases having a low number of supporting cases. This clinical aid supports paediatric dentists in differential diagnosis and onward referral.

Mutational analysis and genotype-phenotype correlation of the PHEX gene in X-linked hypophosphatemic rickets

PHEX is the gene defective in X-linked hypophosphatemic rickets. In this study, analysis of PHEX revealed mutations in 22 hypophosphatemic rickets patients, including 16 of 28 patients in whom all 22 PHEX exons were studied. In 13 patients, in whom no PHEX mutation had been previously detected in 17 exons, the remaining 5 PHEX exons were analyzed and mutations found in 6 patients. Twenty different mutations were identified, including 16 mutations predicted to truncate PHEX and 4 missense mutations. Phenotype analysis was performed on 31 hypophosphatemic rickets patients with PHEX mutations, including the 22 patients identified in this study, 9 patients previously identified, and affected family members. No correlation was found between the severity of disease and the type or location of the mutation. However, among patients with a family history of hypophosphatemic rickets, there was a trend toward more severe skeletal disease in patients with truncating mutations. Family members in more recent generations had a milder phenotype. Postpubertal males had a more severe dental phenotype. In conclusion, although identifying mutations in PHEX may have limited prognostic value, genetic testing may be useful for the early identification and treatment of affected individuals. Furthermore, this study suggests that other genes and environmental factors affect the severity of hypophosphatemic rickets.

Skeletal dysplasia, intracerebral calcifications, optic atrophy, hearing impairment, and mental retardation: nosology of dysosteosclerosis

A girl who presented at 3 months of life with severe developmental delay, blindness, and hearing impairment was found to have intracerebral calcifications. Skeletal films showed craniotubular bone modeling consistent with dysosteosclerosis. The nosology of this disorder is discussed.