The goal of this registry is to collect information on individuals with forms of microcephalic primordial dwarfism as well as related conditions. The study team hopes to learn more about these conditions and improve the care of people with them by establishing this registry.

The registry will enable detailed natural history studies of various forms of microcephalic primordial dwarfism as well as related conditions. The study team hopes that identification of risk factors will allow for preventative treatments and thus a better quality of life for individuals with these diagnoses.

This study is limited to chart review, after signed informed consent obtained. There will be no additional visits or time in clinic because of participation in this registry. This study involves only the collection and storage of data extracted from the medical record. Records that may be requested and reviewed as a part of this study include but may not be limited to: specialist evaluations, surgical reports, results of blood and urine tests, genetic testing, x-rays, CT/MRI/MRA imaging. There are no special procedures, visits, or expectations of the individual as a result of participation in this registry. No one will be asked to have any specific testing for the sole purposes of this research.

Inclusion Criteria:

• Individuals with MOPDII, Meier-Gorlin syndrome, IMAGe syndrome, RNU4atac-opathies (MOPDI/III, Roifman syndrome, Lowry-Wood syndrome), LIG4 syndrome, and other classified as well as unclassified types of microcephalic primordial dwarfism and related conditions, as diagnosed by a medical provider, are eligible for this registry.

Exclusion Criteria:

• individuals without microcephalic primordial dwarfism or closely related conditions

Any individual at any age with microcephalic primordial dwarfism or a closely related condition