People at risk are most likely to get tests in the south-east and in London - and least likely to get them in the north-east, researchers found.
Tests for conditions such as retinitis pigmentosa have been available for longer than a decade.
Researchers say testing can now be done more efficiently using next generation sequencing.
The latest analysis from Manchester University, backed by the charity Fight for Sight, studied the use of tests for six genes linked to inherited and X-linked retinitis pigmentosa.
Researchers found that by 2011 4.5 out of every 100,000 men had been tested - about 1000 in total - as had 2.6 out of every 100,000 women.
Researcher Professor Graeme Black said: "The at-risk population is not uniform across England; the way in which diagnostic tests are made available to clinicians varies between regions; and it's unclear whether there is variation in the way that clinicians and genetic counsellors explain the tests to patients.
"However, it is clear that we are unlikely to achieve equal access across the regions by chance. We need a consistent approach in providing information to patients about the availability and perceived value of testing and we need a strong evidence base to support the value of genetic testing on grounds of clinical and economic utility."
The extent of the crisis was reported as part of the General Election debate focused on mental health.
An investigation by The Times found the longest wait was at the Sussex Partnership NHS Foundation Trust, where a young patient waited three years and 20 weeks for assessments.
At the South London and Maudsley Trust one child waited for a 93 weeks for treatment.
The paper used Freedom of Information requests and found a big increase in referrals of children to mental health trusts - by about 6% between 2013 and 2014.
Meanwhile the Liberal Democrats outlined proposals to increase funding for mental health by £2 billion over the next five years on top of existing government plans.
This would include some £250 million for care of pregnant women and new mothers facing depression. Some of the cash would come from adjusting various tax breaks, Nick Clegg said, saying it was a "liberal mission" to improve mental health care.
Writing in The Guardian, the president of the Royal College of Psychiatrists, Professor Simon Wessely calls for a "change of mind set" throughout the NHS and proper funding for mental health.
Writing in the wake of the Alpine plane crash - attributed to a pilot, reported to have suffered from serious depression - Professor Wessely praises a "more positive" approach to mental illness among politicians.
Professor Wessely states: "Whoever becomes secretary of state for health, it is not enough to stand up in parliament every so often and claim parity of esteem for mental health has been legislated, job done.
"Parity of esteem must be embedded into the mind set of all health professionals, from the secretary of state for health, to local clinical commissioning group commissioners, and from A&E staff to the care worker on the ground making house calls."
Both the Conservatives and Labour have promised to recruit extra GPs and improve access in different ways.
Labour says it wants 8,000 extra GPs while the Conservatives settle for 5,000.
Labour wants to return to guaranteeing patient appointments within 48 hours - while the Conservatives want more out of hours opening.
But an expert at Imperial College, London, Thomas Cowling, says a new government would struggle to recruit extra GPs. He says the promises are "unlikely" to be met within the five years available to the next government.
Writing in The BMJ, Mr Cowling also challenges claims that improving GP care would reduce pressure on hospitals.
He says the UK already has the best access to health care among wealthy nations - and 90% of patients got GP appointments when they want them.
He says a government would do better to examine new ways of having appointments, such as video consultations, and find ways of reducing demand for GP services.
The findings were welcomed by the chair of the British Medical Association's GP committee Dr Chaand Nagpaul, who warned of the need to invest in recruiting GPs.
He said: "It is disappointing that despite the promises made at the start of the general election campaign, politicians are continuing to play games with the future of GP services rather than working on long term solutions to the challenges facing patient care.
"This BMJ study reinforces the BMA’s concerns that evidence is lacking behind current political pledges and that there is little likelihood of achieving the increases in GP numbers proposed within the next Parliament."
He added: "We need a commitment that the next government will not waste resources on schemes that are designed to capture media headlines rather than ensuring GP services are delivering what patients need and deserve."
* The Daily Mail today reports claims that seven-day opening by GPs would cut A&E attendances by two million a year. The conclusions are based on a study conducted in central London.
The BMJ 1 April 2015 [abstract]
Experts set out key areas for research, aimed at applying the latest genetic and diagnostic techniques to the disease.
The guidelines were published jointly by the European Respiratory Society and the American Thoracic Society.
They include calls for research on the effectiveness of long-term oxygen therapy and of non-invasive mechanical ventilation.
Professor Guy Brusselle, from the European Respiratory Society, said: “The World Health Organisation predicts that COPD will become the third leading cause of death worldwide by 2030. It is therefore a critical time for us to act on improving the management of people with the condition.
"This document provides us with a valuable point of reference for identifying the most effective types of research in the field of COPD.
"By identifying the right questions to ask, we aim to improve the diagnosis, assessment and treatment of people with COPD.”
An Official American Thoracic Society / European Respiratory Society Statement: Research Questions in Chronic Obstructive Pulmonary Disease European Respiratory Journal 1 April 2015; doi: 10.1183/09031936.0009015 [abstract]